diff --git a/src/Spout/Writer/Common/Entity/Cell.php b/src/Spout/Common/Entity/Cell.php
similarity index 87%
rename from src/Spout/Writer/Common/Entity/Cell.php
rename to src/Spout/Common/Entity/Cell.php
index caeac53..f1f7c1d 100644
--- a/src/Spout/Writer/Common/Entity/Cell.php
+++ b/src/Spout/Common/Entity/Cell.php
@@ -1,9 +1,9 @@
 <?php
 
-namespace Box\Spout\Writer\Common\Entity;
+namespace Box\Spout\Common\Entity;
 
+use Box\Spout\Common\Entity\Style\Style;
 use Box\Spout\Common\Helper\CellTypeHelper;
-use Box\Spout\Writer\Common\Entity\Style\Style;
 
 /**
  * Class Cell
@@ -36,10 +36,15 @@ class Cell
      */
     const TYPE_BOOLEAN = 4;
 
+    /**
+     * Date cell type
+     */
+    const TYPE_DATE = 5;
+
     /**
      * Error cell type
      */
-    const TYPE_ERROR = 5;
+    const TYPE_ERROR = 6;
 
     /**
      * The value of this cell
@@ -110,6 +115,14 @@ class Cell
         return $this->type;
     }
 
+    /**
+     * @param int $type
+     */
+    public function setType($type)
+    {
+        $this->type = $type;
+    }
+
     /**
      * Get the current value type
      *
@@ -124,9 +137,12 @@ class Cell
         if (CellTypeHelper::isEmpty($value)) {
             return self::TYPE_EMPTY;
         }
-        if (CellTypeHelper::isNumeric($this->getValue())) {
+        if (CellTypeHelper::isNumeric($value)) {
             return self::TYPE_NUMERIC;
         }
+        if (CellTypeHelper::isDateTimeOrDateInterval($value)) {
+            return self::TYPE_DATE;
+        }
         if (CellTypeHelper::isNonEmptyString($value)) {
             return self::TYPE_STRING;
         }
@@ -150,16 +166,6 @@ class Cell
         return $this->type === self::TYPE_EMPTY;
     }
 
-    /**
-     * Not used at the moment
-     *
-     * @return bool
-     */
-    public function isFormula()
-    {
-        return $this->type === self::TYPE_FORMULA;
-    }
-
     /**
      * @return bool
      */
diff --git a/src/Spout/Writer/Common/Entity/Row.php b/src/Spout/Common/Entity/Row.php
similarity index 69%
rename from src/Spout/Writer/Common/Entity/Row.php
rename to src/Spout/Common/Entity/Row.php
index e32166c..a4e5aff 100644
--- a/src/Spout/Writer/Common/Entity/Row.php
+++ b/src/Spout/Common/Entity/Row.php
@@ -1,8 +1,8 @@
 <?php
 
-namespace Box\Spout\Writer\Common\Entity;
+namespace Box\Spout\Common\Entity;
 
-use Box\Spout\Writer\Common\Entity\Style\Style;
+use Box\Spout\Common\Entity\Style\Style;
 
 class Row
 {
@@ -40,7 +40,7 @@ class Row
 
     /**
      * @param Cell[] $cells
-     * @return $this
+     * @return Row
      */
     public function setCells(array $cells)
     {
@@ -53,20 +53,14 @@ class Row
     }
 
     /**
-     * @return Style
-     */
-    public function getStyle()
-    {
-        return $this->style;
-    }
-
-    /**
-     * @param Style|null $style
+     * @param Cell $cell
+     * @param mixed $cellIndex
+     * @parma int $cellIndex
      * @return Row
      */
-    public function setStyle($style)
+    public function setCellAtIndex(Cell $cell, $cellIndex)
     {
-        $this->style = $style ?: new Style();
+        $this->cells[$cellIndex] = $cell;
 
         return $this;
     }
@@ -89,4 +83,33 @@ class Row
     {
         return count($this->cells);
     }
+
+    /**
+     * @return Style
+     */
+    public function getStyle()
+    {
+        return $this->style;
+    }
+
+    /**
+     * @param Style|null $style
+     * @return Row
+     */
+    public function setStyle($style)
+    {
+        $this->style = $style ?: new Style();
+
+        return $this;
+    }
+
+    /**
+     * @return array The row values, as array
+     */
+    public function toArray()
+    {
+        return array_map(function (Cell $cell) {
+            return !$cell->isError() ? $cell->getValue() : null;
+        }, $this->cells);
+    }
 }
diff --git a/src/Spout/Writer/Common/Entity/Style/Border.php b/src/Spout/Common/Entity/Style/Border.php
similarity index 97%
rename from src/Spout/Writer/Common/Entity/Style/Border.php
rename to src/Spout/Common/Entity/Style/Border.php
index ba5d1a2..bbf43ad 100644
--- a/src/Spout/Writer/Common/Entity/Style/Border.php
+++ b/src/Spout/Common/Entity/Style/Border.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Box\Spout\Writer\Common\Entity\Style;
+namespace Box\Spout\Common\Entity\Style;
 
 /**
  * Class Border
diff --git a/src/Spout/Writer/Common/Entity/Style/BorderPart.php b/src/Spout/Common/Entity/Style/BorderPart.php
similarity index 98%
rename from src/Spout/Writer/Common/Entity/Style/BorderPart.php
rename to src/Spout/Common/Entity/Style/BorderPart.php
index cbc6a62..4dcfd82 100644
--- a/src/Spout/Writer/Common/Entity/Style/BorderPart.php
+++ b/src/Spout/Common/Entity/Style/BorderPart.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Box\Spout\Writer\Common\Entity\Style;
+namespace Box\Spout\Common\Entity\Style;
 
 use Box\Spout\Writer\Exception\Border\InvalidNameException;
 use Box\Spout\Writer\Exception\Border\InvalidStyleException;
diff --git a/src/Spout/Writer/Common/Entity/Style/Color.php b/src/Spout/Common/Entity/Style/Color.php
similarity index 93%
rename from src/Spout/Writer/Common/Entity/Style/Color.php
rename to src/Spout/Common/Entity/Style/Color.php
index 1f85da9..36b3d26 100644
--- a/src/Spout/Writer/Common/Entity/Style/Color.php
+++ b/src/Spout/Common/Entity/Style/Color.php
@@ -1,8 +1,8 @@
 <?php
 
-namespace Box\Spout\Writer\Common\Entity\Style;
+namespace Box\Spout\Common\Entity\Style;
 
-use Box\Spout\Writer\Exception\InvalidColorException;
+use Box\Spout\Common\Exception\InvalidColorException;
 
 /**
  * Class Color
@@ -49,7 +49,7 @@ class Color
      * Throws an exception is the color component value is outside of bounds (0 - 255)
      *
      * @param int $colorComponent
-     * @throws \Box\Spout\Writer\Exception\InvalidColorException
+     * @throws \Box\Spout\Common\Exception\InvalidColorException
      * @return void
      */
     protected static function throwIfInvalidColorComponentValue($colorComponent)
diff --git a/src/Spout/Writer/Common/Entity/Style/Style.php b/src/Spout/Common/Entity/Style/Style.php
similarity index 99%
rename from src/Spout/Writer/Common/Entity/Style/Style.php
rename to src/Spout/Common/Entity/Style/Style.php
index a8018e8..b34e036 100644
--- a/src/Spout/Writer/Common/Entity/Style/Style.php
+++ b/src/Spout/Common/Entity/Style/Style.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Box\Spout\Writer\Common\Entity\Style;
+namespace Box\Spout\Common\Entity\Style;
 
 /**
  * Class Style
diff --git a/src/Spout/Common/Exception/InvalidColorException.php b/src/Spout/Common/Exception/InvalidColorException.php
new file mode 100644
index 0000000..f0c6ec9
--- /dev/null
+++ b/src/Spout/Common/Exception/InvalidColorException.php
@@ -0,0 +1,10 @@
+<?php
+
+namespace Box\Spout\Common\Exception;
+
+/**
+ * Class InvalidColorException
+ */
+class InvalidColorException extends SpoutException
+{
+}
diff --git a/src/Spout/Reader/CSV/Creator/InternalEntityFactory.php b/src/Spout/Reader/CSV/Creator/InternalEntityFactory.php
index f4e3c53..cdb4197 100644
--- a/src/Spout/Reader/CSV/Creator/InternalEntityFactory.php
+++ b/src/Spout/Reader/CSV/Creator/InternalEntityFactory.php
@@ -3,11 +3,11 @@
 namespace Box\Spout\Reader\CSV\Creator;
 
 use Box\Spout\Common\Creator\HelperFactory;
+use Box\Spout\Common\Entity\Cell;
+use Box\Spout\Common\Entity\Row;
 use Box\Spout\Common\Helper\GlobalFunctionsHelper;
 use Box\Spout\Common\Manager\OptionsManagerInterface;
 use Box\Spout\Reader\Common\Creator\InternalEntityFactoryInterface;
-use Box\Spout\Reader\Common\Entity\Cell;
-use Box\Spout\Reader\Common\Entity\Row;
 use Box\Spout\Reader\CSV\RowIterator;
 use Box\Spout\Reader\CSV\Sheet;
 use Box\Spout\Reader\CSV\SheetIterator;
@@ -71,7 +71,7 @@ class InternalEntityFactory implements InternalEntityFactoryInterface
      */
     public function createRow(array $cells = [])
     {
-        return new Row($cells);
+        return new Row($cells, null);
     }
 
     /**
diff --git a/src/Spout/Reader/CSV/RowIterator.php b/src/Spout/Reader/CSV/RowIterator.php
index 04ec4f5..bec3072 100644
--- a/src/Spout/Reader/CSV/RowIterator.php
+++ b/src/Spout/Reader/CSV/RowIterator.php
@@ -2,11 +2,11 @@
 
 namespace Box\Spout\Reader\CSV;
 
+use Box\Spout\Common\Entity\Row;
 use Box\Spout\Common\Helper\EncodingHelper;
 use Box\Spout\Common\Helper\GlobalFunctionsHelper;
 use Box\Spout\Common\Manager\OptionsManagerInterface;
 use Box\Spout\Reader\Common\Entity\Options;
-use Box\Spout\Reader\Common\Entity\Row;
 use Box\Spout\Reader\CSV\Creator\InternalEntityFactory;
 use Box\Spout\Reader\IteratorInterface;
 
diff --git a/src/Spout/Reader/Common/Creator/InternalEntityFactoryInterface.php b/src/Spout/Reader/Common/Creator/InternalEntityFactoryInterface.php
index 9f9fd04..c1c78f1 100644
--- a/src/Spout/Reader/Common/Creator/InternalEntityFactoryInterface.php
+++ b/src/Spout/Reader/Common/Creator/InternalEntityFactoryInterface.php
@@ -2,8 +2,8 @@
 
 namespace Box\Spout\Reader\Common\Creator;
 
-use Box\Spout\Reader\Common\Entity\Cell;
-use Box\Spout\Reader\Common\Entity\Row;
+use Box\Spout\Common\Entity\Cell;
+use Box\Spout\Common\Entity\Row;
 
 /**
  * Interface EntityFactoryInterface
diff --git a/src/Spout/Reader/Common/Entity/Cell.php b/src/Spout/Reader/Common/Entity/Cell.php
deleted file mode 100644
index facf148..0000000
--- a/src/Spout/Reader/Common/Entity/Cell.php
+++ /dev/null
@@ -1,175 +0,0 @@
-<?php
-
-namespace Box\Spout\Reader\Common\Entity;
-
-use Box\Spout\Common\Helper\CellTypeHelper;
-
-/**
- * Class Cell
- */
-class Cell
-{
-    /**
-     * Numeric cell type (whole numbers, fractional numbers, dates)
-     */
-    const TYPE_NUMERIC = 0;
-
-    /**
-     * String (text) cell type
-     */
-    const TYPE_STRING = 1;
-
-    /**
-     * Formula cell type
-     * Not used at the moment
-     */
-    const TYPE_FORMULA = 2;
-
-    /**
-     * Empty cell type
-     */
-    const TYPE_EMPTY = 3;
-
-    /**
-     * Boolean cell type
-     */
-    const TYPE_BOOLEAN = 4;
-
-    /**
-     * Date cell type
-     */
-    const TYPE_DATE = 5;
-
-    /**
-     * Error cell type
-     */
-    const TYPE_ERROR = 6;
-
-    /**
-     * The value of this cell
-     * @var mixed|null
-     */
-    protected $value;
-
-    /**
-     * The cell type
-     * @var int|null
-     */
-    protected $type;
-
-    /**
-     * @param $value mixed
-     */
-    public function __construct($value)
-    {
-        $this->setValue($value);
-    }
-
-    /**
-     * @param mixed|null $value
-     */
-    public function setValue($value)
-    {
-        $this->value = $value;
-        $this->type = $this->detectType($value);
-    }
-
-    /**
-     * @return mixed|null
-     */
-    public function getValue()
-    {
-        return $this->value;
-    }
-
-    /**
-     * @return int|null
-     */
-    public function getType()
-    {
-        return $this->type;
-    }
-
-    /**
-     * @param int $type
-     */
-    public function setType($type)
-    {
-        $this->type = $type;
-    }
-
-    /**
-     * Get the current value type
-     *
-     * @param mixed|null $value
-     * @return int
-     */
-    protected function detectType($value)
-    {
-        if (CellTypeHelper::isBoolean($value)) {
-            return self::TYPE_BOOLEAN;
-        }
-        if (CellTypeHelper::isEmpty($value)) {
-            return self::TYPE_EMPTY;
-        }
-        if (CellTypeHelper::isNumeric($value)) {
-            return self::TYPE_NUMERIC;
-        }
-        if (CellTypeHelper::isDateTimeOrDateInterval($value)) {
-            return self::TYPE_DATE;
-        }
-        if (CellTypeHelper::isNonEmptyString($value)) {
-            return self::TYPE_STRING;
-        }
-
-        return self::TYPE_ERROR;
-    }
-
-    /**
-     * @return bool
-     */
-    public function isBoolean()
-    {
-        return $this->type === self::TYPE_BOOLEAN;
-    }
-
-    /**
-     * @return bool
-     */
-    public function isEmpty()
-    {
-        return $this->type === self::TYPE_EMPTY;
-    }
-
-    /**
-     * @return bool
-     */
-    public function isNumeric()
-    {
-        return $this->type === self::TYPE_NUMERIC;
-    }
-
-    /**
-     * @return bool
-     */
-    public function isString()
-    {
-        return $this->type === self::TYPE_STRING;
-    }
-
-    /**
-     * @return bool
-     */
-    public function isError()
-    {
-        return $this->type === self::TYPE_ERROR;
-    }
-
-    /**
-     * @return string
-     */
-    public function __toString()
-    {
-        return (string) $this->value;
-    }
-}
diff --git a/src/Spout/Reader/Common/Entity/Row.php b/src/Spout/Reader/Common/Entity/Row.php
deleted file mode 100644
index 84ff56e..0000000
--- a/src/Spout/Reader/Common/Entity/Row.php
+++ /dev/null
@@ -1,85 +0,0 @@
-<?php
-
-namespace Box\Spout\Reader\Common\Entity;
-
-class Row
-{
-    /**
-     * The cells in this row
-     * @var Cell[]
-     */
-    protected $cells = [];
-
-    /**
-     * Row constructor.
-     * @param Cell[] $cells
-     */
-    public function __construct(array $cells)
-    {
-        $this->setCells($cells);
-    }
-
-    /**
-     * @return Cell[] $cells
-     */
-    public function getCells()
-    {
-        return $this->cells;
-    }
-
-    /**
-     * @param Cell[] $cells
-     * @return Row
-     */
-    public function setCells(array $cells)
-    {
-        $this->cells = [];
-        foreach ($cells as $cell) {
-            $this->addCell($cell);
-        }
-
-        return $this;
-    }
-
-    /**
-     * @param Cell $cell
-     * @param mixed $cellIndex
-     * @parma int $cellIndex
-     * @return Row
-     */
-    public function setCellAtIndex(Cell $cell, $cellIndex)
-    {
-        $this->cells[$cellIndex] = $cell;
-
-        return $this;
-    }
-
-    /**
-     * @param Cell $cell
-     * @return Row
-     */
-    public function addCell(Cell $cell)
-    {
-        $this->cells[] = $cell;
-
-        return $this;
-    }
-
-    /**
-     * @return int
-     */
-    public function getNumCells()
-    {
-        return count($this->cells);
-    }
-
-    /**
-     * @return array The row values, as array
-     */
-    public function toArray()
-    {
-        return array_map(function (Cell $cell) {
-            return !$cell->isError() ? $cell->getValue() : null;
-        }, $this->cells);
-    }
-}
diff --git a/src/Spout/Reader/Common/Manager/RowManager.php b/src/Spout/Reader/Common/Manager/RowManager.php
index f0b55ff..ea76255 100644
--- a/src/Spout/Reader/Common/Manager/RowManager.php
+++ b/src/Spout/Reader/Common/Manager/RowManager.php
@@ -2,8 +2,8 @@
 
 namespace Box\Spout\Reader\Common\Manager;
 
+use Box\Spout\Common\Entity\Row;
 use Box\Spout\Reader\Common\Creator\InternalEntityFactoryInterface;
-use Box\Spout\Reader\Common\Entity\Row;
 
 /**
  * Class RowManager
diff --git a/src/Spout/Reader/ODS/Creator/InternalEntityFactory.php b/src/Spout/Reader/ODS/Creator/InternalEntityFactory.php
index 04c212c..cb06ce2 100644
--- a/src/Spout/Reader/ODS/Creator/InternalEntityFactory.php
+++ b/src/Spout/Reader/ODS/Creator/InternalEntityFactory.php
@@ -2,10 +2,10 @@
 
 namespace Box\Spout\Reader\ODS\Creator;
 
+use Box\Spout\Common\Entity\Cell;
+use Box\Spout\Common\Entity\Row;
 use Box\Spout\Reader\Common\Creator\InternalEntityFactoryInterface;
-use Box\Spout\Reader\Common\Entity\Cell;
 use Box\Spout\Reader\Common\Entity\Options;
-use Box\Spout\Reader\Common\Entity\Row;
 use Box\Spout\Reader\Common\XMLProcessor;
 use Box\Spout\Reader\ODS\RowIterator;
 use Box\Spout\Reader\ODS\Sheet;
@@ -84,7 +84,7 @@ class InternalEntityFactory implements InternalEntityFactoryInterface
      */
     public function createRow(array $cells = [])
     {
-        return new Row($cells);
+        return new Row($cells, null);
     }
 
     /**
diff --git a/src/Spout/Reader/ODS/RowIterator.php b/src/Spout/Reader/ODS/RowIterator.php
index ce61a32..81f0953 100644
--- a/src/Spout/Reader/ODS/RowIterator.php
+++ b/src/Spout/Reader/ODS/RowIterator.php
@@ -2,11 +2,11 @@
 
 namespace Box\Spout\Reader\ODS;
 
+use Box\Spout\Common\Entity\Cell;
+use Box\Spout\Common\Entity\Row;
 use Box\Spout\Common\Exception\IOException;
 use Box\Spout\Common\Manager\OptionsManagerInterface;
-use Box\Spout\Reader\Common\Entity\Cell;
 use Box\Spout\Reader\Common\Entity\Options;
-use Box\Spout\Reader\Common\Entity\Row;
 use Box\Spout\Reader\Common\Manager\RowManager;
 use Box\Spout\Reader\Common\XMLProcessor;
 use Box\Spout\Reader\Exception\InvalidValueException;
diff --git a/src/Spout/Reader/XLSX/Creator/InternalEntityFactory.php b/src/Spout/Reader/XLSX/Creator/InternalEntityFactory.php
index 16966b2..1ebc22f 100644
--- a/src/Spout/Reader/XLSX/Creator/InternalEntityFactory.php
+++ b/src/Spout/Reader/XLSX/Creator/InternalEntityFactory.php
@@ -2,10 +2,10 @@
 
 namespace Box\Spout\Reader\XLSX\Creator;
 
+use Box\Spout\Common\Entity\Cell;
+use Box\Spout\Common\Entity\Row;
 use Box\Spout\Reader\Common\Creator\InternalEntityFactoryInterface;
-use Box\Spout\Reader\Common\Entity\Cell;
 use Box\Spout\Reader\Common\Entity\Options;
-use Box\Spout\Reader\Common\Entity\Row;
 use Box\Spout\Reader\Common\XMLProcessor;
 use Box\Spout\Reader\Wrapper\XMLReader;
 use Box\Spout\Reader\XLSX\Manager\SharedStringsManager;
@@ -118,7 +118,7 @@ class InternalEntityFactory implements InternalEntityFactoryInterface
      */
     public function createRow(array $cells = [])
     {
-        return new Row($cells);
+        return new Row($cells, null);
     }
 
     /**
diff --git a/src/Spout/Reader/XLSX/RowIterator.php b/src/Spout/Reader/XLSX/RowIterator.php
index aaa9789..f161425 100644
--- a/src/Spout/Reader/XLSX/RowIterator.php
+++ b/src/Spout/Reader/XLSX/RowIterator.php
@@ -2,9 +2,9 @@
 
 namespace Box\Spout\Reader\XLSX;
 
+use Box\Spout\Common\Entity\Cell;
+use Box\Spout\Common\Entity\Row;
 use Box\Spout\Common\Exception\IOException;
-use Box\Spout\Reader\Common\Entity\Cell;
-use Box\Spout\Reader\Common\Entity\Row;
 use Box\Spout\Reader\Common\Manager\RowManager;
 use Box\Spout\Reader\Common\XMLProcessor;
 use Box\Spout\Reader\Exception\InvalidValueException;
diff --git a/src/Spout/Writer/CSV/Writer.php b/src/Spout/Writer/CSV/Writer.php
index 12c1823..ffa42ba 100644
--- a/src/Spout/Writer/CSV/Writer.php
+++ b/src/Spout/Writer/CSV/Writer.php
@@ -2,10 +2,10 @@
 
 namespace Box\Spout\Writer\CSV;
 
+use Box\Spout\Common\Entity\Row;
 use Box\Spout\Common\Exception\IOException;
 use Box\Spout\Common\Helper\EncodingHelper;
 use Box\Spout\Writer\Common\Entity\Options;
-use Box\Spout\Writer\Common\Entity\Row;
 use Box\Spout\Writer\WriterAbstract;
 
 /**
diff --git a/src/Spout/Writer/Common/Creator/EntityFactory.php b/src/Spout/Writer/Common/Creator/EntityFactory.php
index 76bf8da..edca067 100644
--- a/src/Spout/Writer/Common/Creator/EntityFactory.php
+++ b/src/Spout/Writer/Common/Creator/EntityFactory.php
@@ -2,9 +2,9 @@
 
 namespace Box\Spout\Writer\Common\Creator;
 
-use Box\Spout\Writer\Common\Entity\Cell;
-use Box\Spout\Writer\Common\Entity\Row;
-use Box\Spout\Writer\Common\Entity\Style\Style;
+use Box\Spout\Common\Entity\Cell;
+use Box\Spout\Common\Entity\Row;
+use Box\Spout\Common\Entity\Style\Style;
 use Box\Spout\Writer\WriterInterface;
 
 /**
diff --git a/src/Spout/Writer/Common/Creator/Style/BorderBuilder.php b/src/Spout/Writer/Common/Creator/Style/BorderBuilder.php
index f85b1a9..9987f1b 100644
--- a/src/Spout/Writer/Common/Creator/Style/BorderBuilder.php
+++ b/src/Spout/Writer/Common/Creator/Style/BorderBuilder.php
@@ -2,9 +2,9 @@
 
 namespace Box\Spout\Writer\Common\Creator\Style;
 
-use Box\Spout\Writer\Common\Entity\Style\Border;
-use Box\Spout\Writer\Common\Entity\Style\BorderPart;
-use Box\Spout\Writer\Common\Entity\Style\Color;
+use Box\Spout\Common\Entity\Style\Border;
+use Box\Spout\Common\Entity\Style\BorderPart;
+use Box\Spout\Common\Entity\Style\Color;
 
 /**
  * Class BorderBuilder
diff --git a/src/Spout/Writer/Common/Creator/Style/StyleBuilder.php b/src/Spout/Writer/Common/Creator/Style/StyleBuilder.php
index 0432ccf..a35a280 100644
--- a/src/Spout/Writer/Common/Creator/Style/StyleBuilder.php
+++ b/src/Spout/Writer/Common/Creator/Style/StyleBuilder.php
@@ -2,8 +2,8 @@
 
 namespace Box\Spout\Writer\Common\Creator\Style;
 
-use Box\Spout\Writer\Common\Entity\Style\Border;
-use Box\Spout\Writer\Common\Entity\Style\Style;
+use Box\Spout\Common\Entity\Style\Border;
+use Box\Spout\Common\Entity\Style\Style;
 
 /**
  * Class StyleBuilder
diff --git a/src/Spout/Writer/Common/Manager/CellManager.php b/src/Spout/Writer/Common/Manager/CellManager.php
index 855c498..248aed4 100644
--- a/src/Spout/Writer/Common/Manager/CellManager.php
+++ b/src/Spout/Writer/Common/Manager/CellManager.php
@@ -2,8 +2,8 @@
 
 namespace Box\Spout\Writer\Common\Manager;
 
-use Box\Spout\Writer\Common\Entity\Cell;
-use Box\Spout\Writer\Common\Entity\Style\Style;
+use Box\Spout\Common\Entity\Cell;
+use Box\Spout\Common\Entity\Style\Style;
 use Box\Spout\Writer\Common\Manager\Style\StyleMerger;
 
 class CellManager
diff --git a/src/Spout/Writer/Common/Manager/RowManager.php b/src/Spout/Writer/Common/Manager/RowManager.php
index 05042a0..75b4b3a 100644
--- a/src/Spout/Writer/Common/Manager/RowManager.php
+++ b/src/Spout/Writer/Common/Manager/RowManager.php
@@ -2,7 +2,7 @@
 
 namespace Box\Spout\Writer\Common\Manager;
 
-use Box\Spout\Writer\Common\Entity\Row;
+use Box\Spout\Common\Entity\Row;
 
 class RowManager
 {
diff --git a/src/Spout/Writer/Common/Manager/Style/StyleManager.php b/src/Spout/Writer/Common/Manager/Style/StyleManager.php
index 9006d02..36abdc3 100644
--- a/src/Spout/Writer/Common/Manager/Style/StyleManager.php
+++ b/src/Spout/Writer/Common/Manager/Style/StyleManager.php
@@ -2,8 +2,8 @@
 
 namespace Box\Spout\Writer\Common\Manager\Style;
 
-use Box\Spout\Writer\Common\Entity\Cell;
-use Box\Spout\Writer\Common\Entity\Style\Style;
+use Box\Spout\Common\Entity\Cell;
+use Box\Spout\Common\Entity\Style\Style;
 
 /**
  * Class StyleManager
@@ -69,7 +69,7 @@ class StyleManager implements StyleManagerInterface
      *        on the Windows version of Excel...
      *
      * @param Cell $cell The cell the style should be applied to
-     * @return \Box\Spout\Writer\Common\Entity\Style\Style The eventually updated style
+     * @return \Box\Spout\Common\Entity\Style\Style The eventually updated style
      */
     protected function applyWrapTextIfCellContainsNewLine(Cell $cell)
     {
diff --git a/src/Spout/Writer/Common/Manager/Style/StyleManagerInterface.php b/src/Spout/Writer/Common/Manager/Style/StyleManagerInterface.php
index 216b981..312588e 100644
--- a/src/Spout/Writer/Common/Manager/Style/StyleManagerInterface.php
+++ b/src/Spout/Writer/Common/Manager/Style/StyleManagerInterface.php
@@ -2,8 +2,8 @@
 
 namespace Box\Spout\Writer\Common\Manager\Style;
 
-use Box\Spout\Writer\Common\Entity\Cell;
-use Box\Spout\Writer\Common\Entity\Style\Style;
+use Box\Spout\Common\Entity\Cell;
+use Box\Spout\Common\Entity\Style\Style;
 
 /**
  * Interface StyleHManagernterface
diff --git a/src/Spout/Writer/Common/Manager/Style/StyleMerger.php b/src/Spout/Writer/Common/Manager/Style/StyleMerger.php
index d254091..d3446d2 100644
--- a/src/Spout/Writer/Common/Manager/Style/StyleMerger.php
+++ b/src/Spout/Writer/Common/Manager/Style/StyleMerger.php
@@ -2,7 +2,7 @@
 
 namespace Box\Spout\Writer\Common\Manager\Style;
 
-use Box\Spout\Writer\Common\Entity\Style\Style;
+use Box\Spout\Common\Entity\Style\Style;
 
 /**
  * Class StyleMerger
diff --git a/src/Spout/Writer/Common/Manager/Style/StyleRegistry.php b/src/Spout/Writer/Common/Manager/Style/StyleRegistry.php
index e817123..fc978e7 100644
--- a/src/Spout/Writer/Common/Manager/Style/StyleRegistry.php
+++ b/src/Spout/Writer/Common/Manager/Style/StyleRegistry.php
@@ -2,7 +2,7 @@
 
 namespace Box\Spout\Writer\Common\Manager\Style;
 
-use Box\Spout\Writer\Common\Entity\Style\Style;
+use Box\Spout\Common\Entity\Style\Style;
 
 /**
  * Class StyleRegistry
diff --git a/src/Spout/Writer/Common/Manager/WorkbookManagerAbstract.php b/src/Spout/Writer/Common/Manager/WorkbookManagerAbstract.php
index 06f659f..7be5c6e 100644
--- a/src/Spout/Writer/Common/Manager/WorkbookManagerAbstract.php
+++ b/src/Spout/Writer/Common/Manager/WorkbookManagerAbstract.php
@@ -2,12 +2,12 @@
 
 namespace Box\Spout\Writer\Common\Manager;
 
+use Box\Spout\Common\Entity\Row;
 use Box\Spout\Common\Exception\IOException;
 use Box\Spout\Common\Manager\OptionsManagerInterface;
 use Box\Spout\Writer\Common\Creator\InternalEntityFactory;
 use Box\Spout\Writer\Common\Creator\ManagerFactoryInterface;
 use Box\Spout\Writer\Common\Entity\Options;
-use Box\Spout\Writer\Common\Entity\Row;
 use Box\Spout\Writer\Common\Entity\Sheet;
 use Box\Spout\Writer\Common\Entity\Workbook;
 use Box\Spout\Writer\Common\Entity\Worksheet;
diff --git a/src/Spout/Writer/Common/Manager/WorkbookManagerInterface.php b/src/Spout/Writer/Common/Manager/WorkbookManagerInterface.php
index 85b68f5..aed304a 100644
--- a/src/Spout/Writer/Common/Manager/WorkbookManagerInterface.php
+++ b/src/Spout/Writer/Common/Manager/WorkbookManagerInterface.php
@@ -2,8 +2,8 @@
 
 namespace Box\Spout\Writer\Common\Manager;
 
+use Box\Spout\Common\Entity\Row;
 use Box\Spout\Common\Exception\IOException;
-use Box\Spout\Writer\Common\Entity\Row;
 use Box\Spout\Writer\Common\Entity\Sheet;
 use Box\Spout\Writer\Common\Entity\Workbook;
 use Box\Spout\Writer\Common\Entity\Worksheet;
diff --git a/src/Spout/Writer/Common/Manager/WorksheetManagerInterface.php b/src/Spout/Writer/Common/Manager/WorksheetManagerInterface.php
index 4131af3..bb54ee6 100644
--- a/src/Spout/Writer/Common/Manager/WorksheetManagerInterface.php
+++ b/src/Spout/Writer/Common/Manager/WorksheetManagerInterface.php
@@ -2,7 +2,7 @@
 
 namespace Box\Spout\Writer\Common\Manager;
 
-use Box\Spout\Writer\Common\Entity\Row;
+use Box\Spout\Common\Entity\Row;
 use Box\Spout\Writer\Common\Entity\Worksheet;
 
 /**
diff --git a/src/Spout/Writer/Exception/Border/InvalidNameException.php b/src/Spout/Writer/Exception/Border/InvalidNameException.php
index 0807298..8bedc38 100644
--- a/src/Spout/Writer/Exception/Border/InvalidNameException.php
+++ b/src/Spout/Writer/Exception/Border/InvalidNameException.php
@@ -2,7 +2,7 @@
 
 namespace Box\Spout\Writer\Exception\Border;
 
-use Box\Spout\Writer\Common\Entity\Style\BorderPart;
+use Box\Spout\Common\Entity\Style\BorderPart;
 use Box\Spout\Writer\Exception\WriterException;
 
 class InvalidNameException extends WriterException
diff --git a/src/Spout/Writer/Exception/Border/InvalidStyleException.php b/src/Spout/Writer/Exception/Border/InvalidStyleException.php
index 2efbded..e4bb145 100644
--- a/src/Spout/Writer/Exception/Border/InvalidStyleException.php
+++ b/src/Spout/Writer/Exception/Border/InvalidStyleException.php
@@ -2,7 +2,7 @@
 
 namespace Box\Spout\Writer\Exception\Border;
 
-use Box\Spout\Writer\Common\Entity\Style\BorderPart;
+use Box\Spout\Common\Entity\Style\BorderPart;
 use Box\Spout\Writer\Exception\WriterException;
 
 class InvalidStyleException extends WriterException
diff --git a/src/Spout/Writer/Exception/Border/InvalidWidthException.php b/src/Spout/Writer/Exception/Border/InvalidWidthException.php
index 9fae1ea..f38d898 100644
--- a/src/Spout/Writer/Exception/Border/InvalidWidthException.php
+++ b/src/Spout/Writer/Exception/Border/InvalidWidthException.php
@@ -2,7 +2,7 @@
 
 namespace Box\Spout\Writer\Exception\Border;
 
-use Box\Spout\Writer\Common\Entity\Style\BorderPart;
+use Box\Spout\Common\Entity\Style\BorderPart;
 use Box\Spout\Writer\Exception\WriterException;
 
 class InvalidWidthException extends WriterException
diff --git a/src/Spout/Writer/Exception/InvalidColorException.php b/src/Spout/Writer/Exception/InvalidColorException.php
deleted file mode 100644
index 250878c..0000000
--- a/src/Spout/Writer/Exception/InvalidColorException.php
+++ /dev/null
@@ -1,10 +0,0 @@
-<?php
-
-namespace Box\Spout\Writer\Exception;
-
-/**
- * Class InvalidColorException
- */
-class InvalidColorException extends WriterException
-{
-}
diff --git a/src/Spout/Writer/ODS/Helper/BorderHelper.php b/src/Spout/Writer/ODS/Helper/BorderHelper.php
index 101bb4c..a53f63c 100644
--- a/src/Spout/Writer/ODS/Helper/BorderHelper.php
+++ b/src/Spout/Writer/ODS/Helper/BorderHelper.php
@@ -2,8 +2,8 @@
 
 namespace Box\Spout\Writer\ODS\Helper;
 
-use Box\Spout\Writer\Common\Entity\Style\Border;
-use Box\Spout\Writer\Common\Entity\Style\BorderPart;
+use Box\Spout\Common\Entity\Style\Border;
+use Box\Spout\Common\Entity\Style\BorderPart;
 
 /**
  * Class BorderHelper
diff --git a/src/Spout/Writer/ODS/Manager/Style/StyleManager.php b/src/Spout/Writer/ODS/Manager/Style/StyleManager.php
index 38b9eb7..5b3bb0d 100644
--- a/src/Spout/Writer/ODS/Manager/Style/StyleManager.php
+++ b/src/Spout/Writer/ODS/Manager/Style/StyleManager.php
@@ -2,7 +2,7 @@
 
 namespace Box\Spout\Writer\ODS\Manager\Style;
 
-use Box\Spout\Writer\Common\Entity\Style\BorderPart;
+use Box\Spout\Common\Entity\Style\BorderPart;
 use Box\Spout\Writer\Common\Entity\Worksheet;
 use Box\Spout\Writer\ODS\Helper\BorderHelper;
 
@@ -189,7 +189,7 @@ EOD;
     /**
      * Returns the contents of the "<style:style>" section, inside "<office:automatic-styles>" section
      *
-     * @param \Box\Spout\Writer\Common\Entity\Style\Style $style
+     * @param \Box\Spout\Common\Entity\Style\Style $style
      * @return string
      */
     protected function getStyleSectionContent($style)
@@ -209,7 +209,7 @@ EOD;
     /**
      * Returns the contents of the "<style:text-properties>" section, inside "<style:style>" section
      *
-     * @param \Box\Spout\Writer\Common\Entity\Style\Style $style
+     * @param \Box\Spout\Common\Entity\Style\Style $style
      * @return string
      */
     private function getTextPropertiesSectionContent($style)
@@ -226,7 +226,7 @@ EOD;
     /**
      * Returns the contents of the "<style:text-properties>" section, inside "<style:style>" section
      *
-     * @param \Box\Spout\Writer\Common\Entity\Style\Style $style
+     * @param \Box\Spout\Common\Entity\Style\Style $style
      * @return string
      */
     private function getFontSectionContent($style)
@@ -271,7 +271,7 @@ EOD;
     /**
      * Returns the contents of the "<style:table-cell-properties>" section, inside "<style:style>" section
      *
-     * @param \Box\Spout\Writer\Common\Entity\Style\Style $style
+     * @param \Box\Spout\Common\Entity\Style\Style $style
      * @return string
      */
     private function getTableCellPropertiesSectionContent($style)
@@ -306,7 +306,7 @@ EOD;
     /**
      * Returns the contents of the borders definition for the "<style:table-cell-properties>" section
      *
-     * @param \Box\Spout\Writer\Common\Entity\Style\Style $style
+     * @param \Box\Spout\Common\Entity\Style\Style $style
      * @return string
      */
     private function getBorderXMLContent($style)
@@ -323,7 +323,7 @@ EOD;
     /**
      * Returns the contents of the background color definition for the "<style:table-cell-properties>" section
      *
-     * @param \Box\Spout\Writer\Common\Entity\Style\Style $style
+     * @param \Box\Spout\Common\Entity\Style\Style $style
      * @return string
      */
     private function getBackgroundColorXMLContent($style)
diff --git a/src/Spout/Writer/ODS/Manager/Style/StyleRegistry.php b/src/Spout/Writer/ODS/Manager/Style/StyleRegistry.php
index 8d4f504..bc9dccc 100644
--- a/src/Spout/Writer/ODS/Manager/Style/StyleRegistry.php
+++ b/src/Spout/Writer/ODS/Manager/Style/StyleRegistry.php
@@ -2,7 +2,7 @@
 
 namespace Box\Spout\Writer\ODS\Manager\Style;
 
-use Box\Spout\Writer\Common\Entity\Style\Style;
+use Box\Spout\Common\Entity\Style\Style;
 
 /**
  * Class StyleRegistry
diff --git a/src/Spout/Writer/ODS/Manager/WorksheetManager.php b/src/Spout/Writer/ODS/Manager/WorksheetManager.php
index 9b260b0..6d76fa0 100644
--- a/src/Spout/Writer/ODS/Manager/WorksheetManager.php
+++ b/src/Spout/Writer/ODS/Manager/WorksheetManager.php
@@ -2,13 +2,13 @@
 
 namespace Box\Spout\Writer\ODS\Manager;
 
+use Box\Spout\Common\Entity\Cell;
+use Box\Spout\Common\Entity\Row;
+use Box\Spout\Common\Entity\Style\Style;
 use Box\Spout\Common\Exception\InvalidArgumentException;
 use Box\Spout\Common\Exception\IOException;
 use Box\Spout\Common\Helper\Escaper\ODS as ODSEscaper;
 use Box\Spout\Common\Helper\StringHelper;
-use Box\Spout\Writer\Common\Entity\Cell;
-use Box\Spout\Writer\Common\Entity\Row;
-use Box\Spout\Writer\Common\Entity\Style\Style;
 use Box\Spout\Writer\Common\Entity\Worksheet;
 use Box\Spout\Writer\Common\Manager\Style\StyleMerger;
 use Box\Spout\Writer\Common\Manager\WorksheetManagerInterface;
diff --git a/src/Spout/Writer/WriterAbstract.php b/src/Spout/Writer/WriterAbstract.php
index 9555d73..4bcc407 100644
--- a/src/Spout/Writer/WriterAbstract.php
+++ b/src/Spout/Writer/WriterAbstract.php
@@ -3,14 +3,14 @@
 namespace Box\Spout\Writer;
 
 use Box\Spout\Common\Creator\HelperFactory;
+use Box\Spout\Common\Entity\Row;
+use Box\Spout\Common\Entity\Style\Style;
 use Box\Spout\Common\Exception\InvalidArgumentException;
 use Box\Spout\Common\Exception\IOException;
 use Box\Spout\Common\Exception\SpoutException;
 use Box\Spout\Common\Helper\GlobalFunctionsHelper;
 use Box\Spout\Common\Manager\OptionsManagerInterface;
 use Box\Spout\Writer\Common\Entity\Options;
-use Box\Spout\Writer\Common\Entity\Row;
-use Box\Spout\Writer\Common\Entity\Style\Style;
 use Box\Spout\Writer\Exception\WriterAlreadyOpenedException;
 use Box\Spout\Writer\Exception\WriterNotOpenedException;
 
diff --git a/src/Spout/Writer/WriterInterface.php b/src/Spout/Writer/WriterInterface.php
index 4e14e8e..89d8749 100644
--- a/src/Spout/Writer/WriterInterface.php
+++ b/src/Spout/Writer/WriterInterface.php
@@ -2,8 +2,8 @@
 
 namespace Box\Spout\Writer;
 
-use Box\Spout\Writer\Common\Entity\Row;
-use Box\Spout\Writer\Common\Entity\Style\Style;
+use Box\Spout\Common\Entity\Row;
+use Box\Spout\Common\Entity\Style\Style;
 
 /**
  * Interface WriterInterface
diff --git a/src/Spout/Writer/WriterMultiSheetsAbstract.php b/src/Spout/Writer/WriterMultiSheetsAbstract.php
index 52a5d8c..8170b67 100644
--- a/src/Spout/Writer/WriterMultiSheetsAbstract.php
+++ b/src/Spout/Writer/WriterMultiSheetsAbstract.php
@@ -3,11 +3,11 @@
 namespace Box\Spout\Writer;
 
 use Box\Spout\Common\Creator\HelperFactory;
+use Box\Spout\Common\Entity\Row;
 use Box\Spout\Common\Helper\GlobalFunctionsHelper;
 use Box\Spout\Common\Manager\OptionsManagerInterface;
 use Box\Spout\Writer\Common\Creator\ManagerFactoryInterface;
 use Box\Spout\Writer\Common\Entity\Options;
-use Box\Spout\Writer\Common\Entity\Row;
 use Box\Spout\Writer\Common\Entity\Sheet;
 use Box\Spout\Writer\Common\Entity\Worksheet;
 use Box\Spout\Writer\Common\Manager\WorkbookManagerInterface;
diff --git a/src/Spout/Writer/XLSX/Helper/BorderHelper.php b/src/Spout/Writer/XLSX/Helper/BorderHelper.php
index 56c1d82..1c773fd 100644
--- a/src/Spout/Writer/XLSX/Helper/BorderHelper.php
+++ b/src/Spout/Writer/XLSX/Helper/BorderHelper.php
@@ -2,8 +2,8 @@
 
 namespace Box\Spout\Writer\XLSX\Helper;
 
-use Box\Spout\Writer\Common\Entity\Style\Border;
-use Box\Spout\Writer\Common\Entity\Style\BorderPart;
+use Box\Spout\Common\Entity\Style\Border;
+use Box\Spout\Common\Entity\Style\BorderPart;
 
 class BorderHelper
 {
diff --git a/src/Spout/Writer/XLSX/Manager/Style/StyleManager.php b/src/Spout/Writer/XLSX/Manager/Style/StyleManager.php
index f5af61f..b98307a 100644
--- a/src/Spout/Writer/XLSX/Manager/Style/StyleManager.php
+++ b/src/Spout/Writer/XLSX/Manager/Style/StyleManager.php
@@ -2,8 +2,8 @@
 
 namespace Box\Spout\Writer\XLSX\Manager\Style;
 
-use Box\Spout\Writer\Common\Entity\Style\Color;
-use Box\Spout\Writer\Common\Entity\Style\Style;
+use Box\Spout\Common\Entity\Style\Color;
+use Box\Spout\Common\Entity\Style\Style;
 use Box\Spout\Writer\XLSX\Helper\BorderHelper;
 
 /**
@@ -153,7 +153,7 @@ EOD;
         $content .= '<border><left/><right/><top/><bottom/></border>';
 
         foreach ($registeredBorders as $styleId) {
-            /** @var \Box\Spout\Writer\Common\Entity\Style\Style $style */
+            /** @var \Box\Spout\Common\Entity\Style\Style $style */
             $style = $this->styleRegistry->getStyleFromStyleId($styleId);
             $border = $style->getBorder();
             $content .= '<border>';
@@ -163,7 +163,7 @@ EOD;
 
             foreach ($sortOrder as $partName) {
                 if ($border->hasPart($partName)) {
-                    /** @var $part \Box\Spout\Writer\Common\Entity\Style\BorderPart */
+                    /** @var $part \Box\Spout\Common\Entity\Style\BorderPart */
                     $part = $border->getPart($partName);
                     $content .= BorderHelper::serializeBorderPart($part);
                 }
diff --git a/src/Spout/Writer/XLSX/Manager/Style/StyleRegistry.php b/src/Spout/Writer/XLSX/Manager/Style/StyleRegistry.php
index 8039454..abd89f1 100644
--- a/src/Spout/Writer/XLSX/Manager/Style/StyleRegistry.php
+++ b/src/Spout/Writer/XLSX/Manager/Style/StyleRegistry.php
@@ -2,7 +2,7 @@
 
 namespace Box\Spout\Writer\XLSX\Manager\Style;
 
-use Box\Spout\Writer\Common\Entity\Style\Style;
+use Box\Spout\Common\Entity\Style\Style;
 
 /**
  * Class StyleRegistry
diff --git a/src/Spout/Writer/XLSX/Manager/WorksheetManager.php b/src/Spout/Writer/XLSX/Manager/WorksheetManager.php
index 702986e..b0e458f 100644
--- a/src/Spout/Writer/XLSX/Manager/WorksheetManager.php
+++ b/src/Spout/Writer/XLSX/Manager/WorksheetManager.php
@@ -2,16 +2,16 @@
 
 namespace Box\Spout\Writer\XLSX\Manager;
 
+use Box\Spout\Common\Entity\Cell;
+use Box\Spout\Common\Entity\Row;
+use Box\Spout\Common\Entity\Style\Style;
 use Box\Spout\Common\Exception\InvalidArgumentException;
 use Box\Spout\Common\Exception\IOException;
 use Box\Spout\Common\Helper\Escaper\XLSX as XLSXEscaper;
 use Box\Spout\Common\Helper\StringHelper;
 use Box\Spout\Common\Manager\OptionsManagerInterface;
 use Box\Spout\Writer\Common\Creator\InternalEntityFactory;
-use Box\Spout\Writer\Common\Entity\Cell;
 use Box\Spout\Writer\Common\Entity\Options;
-use Box\Spout\Writer\Common\Entity\Row;
-use Box\Spout\Writer\Common\Entity\Style\Style;
 use Box\Spout\Writer\Common\Entity\Worksheet;
 use Box\Spout\Writer\Common\Helper\CellHelper;
 use Box\Spout\Writer\Common\Manager\RowManager;
diff --git a/tests/Spout/Reader/Common/Entity/CellTest.php b/tests/Spout/Common/Entity/CellTest.php
similarity index 96%
rename from tests/Spout/Reader/Common/Entity/CellTest.php
rename to tests/Spout/Common/Entity/CellTest.php
index e846f26..7b97850 100644
--- a/tests/Spout/Reader/Common/Entity/CellTest.php
+++ b/tests/Spout/Common/Entity/CellTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace Box\Spout\Reader\Common\Entity;
+namespace Box\Spout\Common\Entity;
 
 class CellTest extends \PHPUnit\Framework\TestCase
 {
diff --git a/tests/Spout/Writer/Common/Entity/RowTest.php b/tests/Spout/Common/Entity/RowTest.php
similarity index 93%
rename from tests/Spout/Writer/Common/Entity/RowTest.php
rename to tests/Spout/Common/Entity/RowTest.php
index 8f1859a..c3ca981 100644
--- a/tests/Spout/Writer/Common/Entity/RowTest.php
+++ b/tests/Spout/Common/Entity/RowTest.php
@@ -1,11 +1,10 @@
 <?php
 
-namespace Box\Spout\Writer\Common\Entity;
+namespace Box\Spout\Common\Entity;
 
-use Box\Spout\Writer\Common\Entity\Style\Style;
-use PHPUnit\Framework\TestCase;
+use Box\Spout\Common\Entity\Style\Style;
 
-class RowTest extends TestCase
+class RowTest extends \PHPUnit\Framework\TestCase
 {
     /**
      * @return \PHPUnit_Framework_MockObject_MockObject|Style
diff --git a/tests/Spout/Writer/Common/Entity/Style/BorderTest.php b/tests/Spout/Common/Entity/Style/BorderTest.php
similarity index 94%
rename from tests/Spout/Writer/Common/Entity/Style/BorderTest.php
rename to tests/Spout/Common/Entity/Style/BorderTest.php
index 33f7e57..c57a8d7 100644
--- a/tests/Spout/Writer/Common/Entity/Style/BorderTest.php
+++ b/tests/Spout/Common/Entity/Style/BorderTest.php
@@ -1,11 +1,8 @@
 <?php
 
-namespace Box\Spout\Writer\Common\EntityStyle;
+namespace Box\Spout\Common\Entity\Style;
 
 use Box\Spout\Writer\Common\Creator\Style\BorderBuilder;
-use Box\Spout\Writer\Common\Entity\Style\Border;
-use Box\Spout\Writer\Common\Entity\Style\BorderPart;
-use Box\Spout\Writer\Common\Entity\Style\Color;
 use Box\Spout\Writer\Exception\Border\InvalidNameException;
 use Box\Spout\Writer\Exception\Border\InvalidStyleException;
 use Box\Spout\Writer\Exception\Border\InvalidWidthException;
diff --git a/tests/Spout/Writer/Common/Entity/Style/ColorTest.php b/tests/Spout/Common/Entity/Style/ColorTest.php
similarity index 95%
rename from tests/Spout/Writer/Common/Entity/Style/ColorTest.php
rename to tests/Spout/Common/Entity/Style/ColorTest.php
index ed5128f..39111b2 100644
--- a/tests/Spout/Writer/Common/Entity/Style/ColorTest.php
+++ b/tests/Spout/Common/Entity/Style/ColorTest.php
@@ -1,8 +1,8 @@
 <?php
 
-namespace Box\Spout\Writer\Common\Entity\Style;
+namespace Box\Spout\Common\Entity\Style;
 
-use Box\Spout\Writer\Exception\InvalidColorException;
+use Box\Spout\Common\Exception\InvalidColorException;
 
 /**
  * Class ColorTest
diff --git a/tests/Spout/Reader/Common/Entity/RowTest.php b/tests/Spout/Reader/Common/Entity/RowTest.php
deleted file mode 100644
index 964c6e7..0000000
--- a/tests/Spout/Reader/Common/Entity/RowTest.php
+++ /dev/null
@@ -1,90 +0,0 @@
-<?php
-
-namespace Box\Spout\Reader\Common\Entity;
-
-class RowTest extends \PHPUnit\Framework\TestCase
-{
-    /**
-     * @return \PHPUnit_Framework_MockObject_MockObject|Cell
-     */
-    private function getCellMock()
-    {
-        return $this->createMock(Cell::class);
-    }
-
-    /**
-     * @return void
-     */
-    public function testValidInstance()
-    {
-        $this->assertInstanceOf(Row::class, new Row([], null));
-    }
-
-    /**
-     * @return void
-     */
-    public function testSetCells()
-    {
-        $row = new Row([], null);
-        $row->setCells([$this->getCellMock(), $this->getCellMock()]);
-
-        $this->assertEquals(2, $row->getNumCells());
-    }
-
-    /**
-     * @return void
-     */
-    public function testSetCellsResets()
-    {
-        $row = new Row([], null);
-        $row->setCells([$this->getCellMock(), $this->getCellMock()]);
-
-        $this->assertEquals(2, $row->getNumCells());
-
-        $row->setCells([$this->getCellMock()]);
-
-        $this->assertEquals(1, $row->getNumCells());
-    }
-
-    /**
-     * @return void
-     */
-    public function testGetCells()
-    {
-        $row = new Row([], null);
-
-        $this->assertEquals(0, $row->getNumCells());
-
-        $row->setCells([$this->getCellMock(), $this->getCellMock()]);
-
-        $this->assertEquals(2, $row->getNumCells());
-    }
-
-    /**
-     * @return void
-     */
-    public function testAddCell()
-    {
-        $row = new Row([], null);
-        $row->setCells([$this->getCellMock(), $this->getCellMock()]);
-
-        $this->assertEquals(2, $row->getNumCells());
-
-        $row->addCell($this->getCellMock());
-
-        $this->assertEquals(3, $row->getNumCells());
-    }
-
-    /**
-     * @return void
-     */
-    public function testFluentInterface()
-    {
-        $row = new Row([], null);
-        $row
-            ->addCell($this->getCellMock())
-            ->setCells([]);
-
-        $this->assertTrue(is_object($row));
-    }
-}
diff --git a/tests/Spout/Reader/Common/Manager/RowManagerTest.php b/tests/Spout/Reader/Common/Manager/RowManagerTest.php
index b17eb04..8afd39f 100644
--- a/tests/Spout/Reader/Common/Manager/RowManagerTest.php
+++ b/tests/Spout/Reader/Common/Manager/RowManagerTest.php
@@ -2,8 +2,8 @@
 
 namespace Box\Spout\Reader\Common\Manager;
 
-use Box\Spout\Reader\Common\Entity\Cell;
-use Box\Spout\Reader\Common\Entity\Row;
+use Box\Spout\Common\Entity\Cell;
+use Box\Spout\Common\Entity\Row;
 use Box\Spout\Reader\XLSX\Creator\HelperFactory;
 use Box\Spout\Reader\XLSX\Creator\InternalEntityFactory;
 use Box\Spout\Reader\XLSX\Creator\ManagerFactory;
@@ -37,7 +37,7 @@ class RowManagerTest extends \PHPUnit_Framework_TestCase
     {
         $rowManager = $this->createRowManager();
 
-        $rowToFill = new Row([]);
+        $rowToFill = new Row([], null);
         foreach ($rowCells as $cellIndex => $cell) {
             $rowToFill->setCellAtIndex($cell, $cellIndex);
         }
@@ -70,7 +70,7 @@ class RowManagerTest extends \PHPUnit_Framework_TestCase
     public function testIsEmptyRow(array $cells, $expectedIsEmpty)
     {
         $rowManager = $this->createRowManager();
-        $row = new Row($cells);
+        $row = new Row($cells, null);
 
         $this->assertEquals($expectedIsEmpty, $rowManager->isEmpty($row));
     }
diff --git a/tests/Spout/Reader/XLSX/Helper/CellValueFormatterTest.php b/tests/Spout/Reader/XLSX/Helper/CellValueFormatterTest.php
index 288e599..86322ee 100644
--- a/tests/Spout/Reader/XLSX/Helper/CellValueFormatterTest.php
+++ b/tests/Spout/Reader/XLSX/Helper/CellValueFormatterTest.php
@@ -104,7 +104,7 @@ class CellValueFormatterTest extends \PHPUnit_Framework_TestCase
             if ($expectedDateAsString === null) {
                 $this->fail('An exception should have been thrown');
             } else {
-                $this->assertInstanceOf('DateTime', $result);
+                $this->assertInstanceOf(\DateTime::class, $result);
                 $this->assertSame($expectedDateAsString, $result->format('Y-m-d H:i:s'));
             }
         } catch (InvalidValueException $exception) {
diff --git a/tests/Spout/Writer/CSV/WriterTest.php b/tests/Spout/Writer/CSV/WriterTest.php
index 63a7d7c..d10d0b3 100644
--- a/tests/Spout/Writer/CSV/WriterTest.php
+++ b/tests/Spout/Writer/CSV/WriterTest.php
@@ -2,13 +2,13 @@
 
 namespace Box\Spout\Writer\CSV;
 
+use Box\Spout\Common\Entity\Row;
 use Box\Spout\Common\Exception\InvalidArgumentException;
 use Box\Spout\Common\Exception\IOException;
 use Box\Spout\Common\Helper\EncodingHelper;
 use Box\Spout\Common\Type;
 use Box\Spout\TestUsingResource;
 use Box\Spout\Writer\Common\Creator\EntityFactory;
-use Box\Spout\Writer\Common\Entity\Row;
 use Box\Spout\Writer\Exception\WriterNotOpenedException;
 use Box\Spout\Writer\RowCreationHelper;
 
diff --git a/tests/Spout/Writer/Common/Creator/StyleBuilderTest.php b/tests/Spout/Writer/Common/Creator/StyleBuilderTest.php
index 36e94d4..cbe6003 100644
--- a/tests/Spout/Writer/Common/Creator/StyleBuilderTest.php
+++ b/tests/Spout/Writer/Common/Creator/StyleBuilderTest.php
@@ -2,8 +2,8 @@
 
 namespace Box\Spout\Writer\Common\Creator\Style;
 
-use Box\Spout\Writer\Common\Entity\Style\Border;
-use Box\Spout\Writer\Common\Entity\Style\Color;
+use Box\Spout\Common\Entity\Style\Border;
+use Box\Spout\Common\Entity\Style\Color;
 use Box\Spout\Writer\Common\Manager\Style\StyleMerger;
 
 /**
@@ -37,7 +37,7 @@ class StyleBuilderTest extends \PHPUnit_Framework_TestCase
         $mergedStyle = $styleMerger->merge($currentStyle, $baseStyle);
 
         $this->assertEquals(null, $currentStyle->getBorder(), 'Current style has no border');
-        $this->assertInstanceOf('Box\Spout\Writer\Common\Entity\Style\Border', $baseStyle->getBorder(), 'Base style has a border');
-        $this->assertInstanceOf('Box\Spout\Writer\Common\Entity\Style\Border', $mergedStyle->getBorder(), 'Merged style has a border');
+        $this->assertInstanceOf(Border::class, $baseStyle->getBorder(), 'Base style has a border');
+        $this->assertInstanceOf(Border::class, $mergedStyle->getBorder(), 'Merged style has a border');
     }
 }
diff --git a/tests/Spout/Writer/Common/Entity/CellTest.php b/tests/Spout/Writer/Common/Entity/CellTest.php
deleted file mode 100644
index e31a0b2..0000000
--- a/tests/Spout/Writer/Common/Entity/CellTest.php
+++ /dev/null
@@ -1,68 +0,0 @@
-<?php
-
-namespace Box\Spout\Writer\Common\Entity;
-
-use Box\Spout\Writer\Common\Entity\Style\Style;
-use PHPUnit\Framework\TestCase;
-
-class CellTest extends TestCase
-{
-    /**
-     * @return void
-     */
-    public function testValidInstance()
-    {
-        $this->assertInstanceOf(Cell::class, new Cell('cell'));
-        $this->assertInstanceOf(Cell::class, new Cell('cell-with-style', $this->createMock(Style::class)));
-    }
-
-    /**
-     * @return void
-     */
-    public function testCellTypeNumeric()
-    {
-        $this->assertTrue((new Cell(0))->isNumeric());
-        $this->assertTrue((new Cell(1))->isNumeric());
-    }
-
-    /**
-     * @return void
-     */
-    public function testCellTypeString()
-    {
-        $this->assertTrue((new Cell('String!'))->isString());
-    }
-
-    /**
-     * @return void
-     */
-    public function testCellTypeEmptyString()
-    {
-        $this->assertTrue((new Cell(''))->isEmpty());
-    }
-
-    /**
-     * @return void
-     */
-    public function testCellTypeEmptyNull()
-    {
-        $this->assertTrue((new Cell(null))->isEmpty());
-    }
-
-    /**
-     * @return void
-     */
-    public function testCellTypeBool()
-    {
-        $this->assertTrue((new Cell(true))->isBoolean());
-        $this->assertTrue((new Cell(false))->isBoolean());
-    }
-
-    /**
-     * @return void
-     */
-    public function testCellTypeError()
-    {
-        $this->assertTrue((new Cell([]))->isError());
-    }
-}
diff --git a/tests/Spout/Writer/Common/Manager/CellManagerTest.php b/tests/Spout/Writer/Common/Manager/CellManagerTest.php
index f10eefd..a1db98a 100644
--- a/tests/Spout/Writer/Common/Manager/CellManagerTest.php
+++ b/tests/Spout/Writer/Common/Manager/CellManagerTest.php
@@ -2,8 +2,8 @@
 
 namespace Spout\Writer\Common\Manager;
 
+use Box\Spout\Common\Entity\Cell;
 use Box\Spout\Writer\Common\Creator\Style\StyleBuilder;
-use Box\Spout\Writer\Common\Entity\Cell;
 use Box\Spout\Writer\Common\Manager\CellManager;
 use Box\Spout\Writer\Common\Manager\Style\StyleMerger;
 use PHPUnit\Framework\TestCase;
diff --git a/tests/Spout/Writer/Common/Manager/RowManagerTest.php b/tests/Spout/Writer/Common/Manager/RowManagerTest.php
index 966f7b9..91ae378 100644
--- a/tests/Spout/Writer/Common/Manager/RowManagerTest.php
+++ b/tests/Spout/Writer/Common/Manager/RowManagerTest.php
@@ -2,8 +2,8 @@
 
 namespace Spout\Writer\Common\Manager;
 
-use Box\Spout\Writer\Common\Entity\Cell;
-use Box\Spout\Writer\Common\Entity\Row;
+use Box\Spout\Common\Entity\Cell;
+use Box\Spout\Common\Entity\Row;
 use Box\Spout\Writer\Common\Manager\RowManager;
 use PHPUnit\Framework\TestCase;
 
diff --git a/tests/Spout/Writer/Common/Manager/Style/StyleManagerTest.php b/tests/Spout/Writer/Common/Manager/Style/StyleManagerTest.php
index f1faae1..81f3477 100644
--- a/tests/Spout/Writer/Common/Manager/Style/StyleManagerTest.php
+++ b/tests/Spout/Writer/Common/Manager/Style/StyleManagerTest.php
@@ -2,8 +2,8 @@
 
 namespace Box\Spout\Writer\Common\Manager\Style;
 
+use Box\Spout\Common\Entity\Cell;
 use Box\Spout\Writer\Common\Creator\Style\StyleBuilder;
-use Box\Spout\Writer\Common\Entity\Cell;
 
 /**
  * Class StyleManagerTest
diff --git a/tests/Spout/Writer/Common/Manager/Style/StyleMergerTest.php b/tests/Spout/Writer/Common/Manager/Style/StyleMergerTest.php
index ed87af4..6ca3232 100644
--- a/tests/Spout/Writer/Common/Manager/Style/StyleMergerTest.php
+++ b/tests/Spout/Writer/Common/Manager/Style/StyleMergerTest.php
@@ -2,9 +2,9 @@
 
 namespace Box\Spout\Writer\Common\Manager\Style;
 
+use Box\Spout\Common\Entity\Style\Color;
+use Box\Spout\Common\Entity\Style\Style;
 use Box\Spout\Writer\Common\Creator\Style\StyleBuilder;
-use Box\Spout\Writer\Common\Entity\Style\Color;
-use Box\Spout\Writer\Common\Entity\Style\Style;
 
 /**
  * Class StyleMergerTest
diff --git a/tests/Spout/Writer/Common/Manager/Style/StyleRegistryTest.php b/tests/Spout/Writer/Common/Manager/Style/StyleRegistryTest.php
index 52a2d36..4a25f34 100644
--- a/tests/Spout/Writer/Common/Manager/Style/StyleRegistryTest.php
+++ b/tests/Spout/Writer/Common/Manager/Style/StyleRegistryTest.php
@@ -2,8 +2,8 @@
 
 namespace Box\Spout\Writer\Common\Manager\Style;
 
+use Box\Spout\Common\Entity\Style\Style;
 use Box\Spout\Writer\Common\Creator\Style\StyleBuilder;
-use Box\Spout\Writer\Common\Entity\Style\Style;
 
 /**
  * Class StyleRegistryTest
diff --git a/tests/Spout/Writer/ODS/WriterTest.php b/tests/Spout/Writer/ODS/WriterTest.php
index 3ec94fc..d2b3bdf 100644
--- a/tests/Spout/Writer/ODS/WriterTest.php
+++ b/tests/Spout/Writer/ODS/WriterTest.php
@@ -2,6 +2,7 @@
 
 namespace Box\Spout\Writer\ODS;
 
+use Box\Spout\Common\Entity\Row;
 use Box\Spout\Common\Exception\InvalidArgumentException;
 use Box\Spout\Common\Exception\IOException;
 use Box\Spout\Common\Exception\SpoutException;
@@ -9,7 +10,6 @@ use Box\Spout\Common\Type;
 use Box\Spout\Reader\Wrapper\XMLReader;
 use Box\Spout\TestUsingResource;
 use Box\Spout\Writer\Common\Creator\EntityFactory;
-use Box\Spout\Writer\Common\Entity\Row;
 use Box\Spout\Writer\Common\Helper\ZipHelper;
 use Box\Spout\Writer\Exception\WriterAlreadyOpenedException;
 use Box\Spout\Writer\Exception\WriterNotOpenedException;
diff --git a/tests/Spout/Writer/ODS/WriterWithStyleTest.php b/tests/Spout/Writer/ODS/WriterWithStyleTest.php
index 6cd54d7..a90bb6c 100644
--- a/tests/Spout/Writer/ODS/WriterWithStyleTest.php
+++ b/tests/Spout/Writer/ODS/WriterWithStyleTest.php
@@ -2,16 +2,16 @@
 
 namespace Box\Spout\Writer\ODS;
 
+use Box\Spout\Common\Entity\Row;
+use Box\Spout\Common\Entity\Style\Border;
+use Box\Spout\Common\Entity\Style\Color;
+use Box\Spout\Common\Entity\Style\Style;
 use Box\Spout\Common\Type;
 use Box\Spout\Reader\Wrapper\XMLReader;
 use Box\Spout\TestUsingResource;
 use Box\Spout\Writer\Common\Creator\EntityFactory;
 use Box\Spout\Writer\Common\Creator\Style\BorderBuilder;
 use Box\Spout\Writer\Common\Creator\Style\StyleBuilder;
-use Box\Spout\Writer\Common\Entity\Row;
-use Box\Spout\Writer\Common\Entity\Style\Border;
-use Box\Spout\Writer\Common\Entity\Style\Color;
-use Box\Spout\Writer\Common\Entity\Style\Style;
 use Box\Spout\Writer\Exception\WriterNotOpenedException;
 use Box\Spout\Writer\RowCreationHelper;
 
diff --git a/tests/Spout/Writer/RowCreationHelper.php b/tests/Spout/Writer/RowCreationHelper.php
index be1336f..6b124f2 100644
--- a/tests/Spout/Writer/RowCreationHelper.php
+++ b/tests/Spout/Writer/RowCreationHelper.php
@@ -2,9 +2,9 @@
 
 namespace Box\Spout\Writer;
 
+use Box\Spout\Common\Entity\Row;
+use Box\Spout\Common\Entity\Style\Style;
 use Box\Spout\Writer\Common\Creator\EntityFactory;
-use Box\Spout\Writer\Common\Entity\Row;
-use Box\Spout\Writer\Common\Entity\Style\Style;
 
 /**
  * Trait RowCreationHelper
diff --git a/tests/Spout/Writer/XLSX/Manager/Style/StyleRegistryTest.php b/tests/Spout/Writer/XLSX/Manager/Style/StyleRegistryTest.php
index 3b77d0b..bea7683 100644
--- a/tests/Spout/Writer/XLSX/Manager/Style/StyleRegistryTest.php
+++ b/tests/Spout/Writer/XLSX/Manager/Style/StyleRegistryTest.php
@@ -2,9 +2,9 @@
 
 namespace Box\Spout\Writer\XLSX\Manager\Style;
 
+use Box\Spout\Common\Entity\Style\Color;
 use Box\Spout\Writer\Common\Creator\Style\BorderBuilder;
 use Box\Spout\Writer\Common\Creator\Style\StyleBuilder;
-use Box\Spout\Writer\Common\Entity\Style\Color;
 
 /**
  * Class StyleRegistryTest
diff --git a/tests/Spout/Writer/XLSX/WriterTest.php b/tests/Spout/Writer/XLSX/WriterTest.php
index f5796de..bd4512c 100644
--- a/tests/Spout/Writer/XLSX/WriterTest.php
+++ b/tests/Spout/Writer/XLSX/WriterTest.php
@@ -2,13 +2,13 @@
 
 namespace Box\Spout\Writer\XLSX;
 
+use Box\Spout\Common\Entity\Row;
 use Box\Spout\Common\Exception\InvalidArgumentException;
 use Box\Spout\Common\Exception\IOException;
 use Box\Spout\Common\Exception\SpoutException;
 use Box\Spout\Common\Type;
 use Box\Spout\TestUsingResource;
 use Box\Spout\Writer\Common\Creator\EntityFactory;
-use Box\Spout\Writer\Common\Entity\Row;
 use Box\Spout\Writer\Exception\WriterAlreadyOpenedException;
 use Box\Spout\Writer\Exception\WriterNotOpenedException;
 use Box\Spout\Writer\RowCreationHelper;
diff --git a/tests/Spout/Writer/XLSX/WriterWithStyleTest.php b/tests/Spout/Writer/XLSX/WriterWithStyleTest.php
index 8565988..50410db 100644
--- a/tests/Spout/Writer/XLSX/WriterWithStyleTest.php
+++ b/tests/Spout/Writer/XLSX/WriterWithStyleTest.php
@@ -2,17 +2,17 @@
 
 namespace Box\Spout\Writer\XLSX;
 
+use Box\Spout\Common\Entity\Cell;
+use Box\Spout\Common\Entity\Row;
+use Box\Spout\Common\Entity\Style\Border;
+use Box\Spout\Common\Entity\Style\Color;
+use Box\Spout\Common\Entity\Style\Style;
 use Box\Spout\Common\Type;
 use Box\Spout\Reader\Wrapper\XMLReader;
 use Box\Spout\TestUsingResource;
 use Box\Spout\Writer\Common\Creator\EntityFactory;
 use Box\Spout\Writer\Common\Creator\Style\BorderBuilder;
 use Box\Spout\Writer\Common\Creator\Style\StyleBuilder;
-use Box\Spout\Writer\Common\Entity\Cell;
-use Box\Spout\Writer\Common\Entity\Row;
-use Box\Spout\Writer\Common\Entity\Style\Border;
-use Box\Spout\Writer\Common\Entity\Style\Color;
-use Box\Spout\Writer\Common\Entity\Style\Style;
 use Box\Spout\Writer\Common\Manager\Style\StyleMerger;
 use Box\Spout\Writer\Exception\WriterNotOpenedException;
 use Box\Spout\Writer\RowCreationHelper;
@@ -26,7 +26,7 @@ class WriterWithStyleTest extends \PHPUnit_Framework_TestCase
     use TestUsingResource;
     use RowCreationHelper;
 
-    /** @var \Box\Spout\Writer\Common\Entity\Style\Style */
+    /** @var \Box\Spout\Common\Entity\Style\Style */
     private $defaultStyle;
 
     /**
@@ -531,7 +531,7 @@ class WriterWithStyleTest extends \PHPUnit_Framework_TestCase
     /**
      * @param Row[] $allRows
      * @param string $fileName
-     * @param \Box\Spout\Writer\Common\Entity\Style\Style|null $defaultStyle
+     * @param \Box\Spout\Common\Entity\Style\Style|null $defaultStyle
      * @return Writer
      */
     private function writeToXLSXFileWithDefaultStyle($allRows, $fileName, $defaultStyle)