diff --git a/src/Spout/Writer/Common/Entity/Row.php b/src/Spout/Writer/Common/Entity/Row.php
index 56e7ab2..bc6f94f 100644
--- a/src/Spout/Writer/Common/Entity/Row.php
+++ b/src/Spout/Writer/Common/Entity/Row.php
@@ -26,7 +26,7 @@ class Row
 
     /**
      * Row constructor.
-     * @param array $cells
+     * @param Cell[] $cells
      * @param Style|null $style
      */
     public function __construct(array $cells = [], Style $style = null)
@@ -39,7 +39,7 @@ class Row
     }
 
     /**
-     * @return array
+     * @return Cell[] $cells
      */
     public function getCells()
     {
@@ -48,9 +48,9 @@ class Row
 
     /**
      * @param array $cells
-     * @return Row
+     * @return $this
      */
-    public function setCells($cells)
+    public function setCells(array $cells)
     {
         $this->cells = [];
         foreach ($cells as $cell) {
@@ -82,7 +82,7 @@ class Row
 
     /**
      * @param Style $style|null
-     * @return $this
+     * @return Row
      */
     public function applyStyle(Style $style = null)
     {
diff --git a/src/Spout/Writer/Common/Manager/CellManager.php b/src/Spout/Writer/Common/Manager/CellManager.php
new file mode 100644
index 0000000..be79b59
--- /dev/null
+++ b/src/Spout/Writer/Common/Manager/CellManager.php
@@ -0,0 +1,37 @@
+<?php
+
+namespace Box\Spout\Writer\Common\Manager;
+
+use Box\Spout\Writer\Common\Entity\Cell;
+use Box\Spout\Writer\Common\Entity\Style\Style;
+use Box\Spout\Writer\Common\Manager\Style\StyleMerger;
+
+class CellManager
+{
+    /**
+     * @var StyleMerger
+     */
+    protected $styleMerger;
+
+    /**
+     * CellManager constructor.
+     * @param StyleMerger $styleMerger
+     */
+    public function __construct(StyleMerger $styleMerger)
+    {
+        $this->styleMerger = $styleMerger;
+    }
+
+    /**
+     * Merges a Style into a cells Style.
+     *
+     * @param Cell $cell
+     * @param Style $style
+     * @return $this
+     */
+    public function applyStyle(Cell $cell, Style $style)
+    {
+        $mergedStyle = $this->styleMerger->merge($cell->getStyle(), $style);
+        $cell->setStyle($mergedStyle);
+    }
+}
\ No newline at end of file
diff --git a/src/Spout/Writer/Common/Manager/RowManager.php b/src/Spout/Writer/Common/Manager/RowManager.php
new file mode 100644
index 0000000..49c6e9d
--- /dev/null
+++ b/src/Spout/Writer/Common/Manager/RowManager.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace Box\Spout\Writer\Common\Manager;
+
+use Box\Spout\Writer\Common\Entity\Row;
+use Box\Spout\Writer\Common\Entity\Style\Style;
+use Box\Spout\Writer\Common\Manager\Style\StyleMerger;
+
+class RowManager
+{
+    /**
+     * @var StyleMerger
+     */
+    protected $styleMerger;
+
+    /**
+     * RowManager constructor.
+     * @param StyleMerger $styleMerger
+     */
+    public function __construct(StyleMerger $styleMerger)
+    {
+        $this->styleMerger = $styleMerger;
+    }
+
+    /**
+     * @param Style $style
+     * @return $this
+     */
+    public function applyStyle(Row $row, Style $style)
+    {
+        $mergedStyle = $this->styleMerger->merge($row->getStyle(), $style);
+        $row->setStyle($mergedStyle);
+    }
+}
\ No newline at end of file
diff --git a/src/Spout/Writer/Common/Manager/WorkbookManagerAbstract.php b/src/Spout/Writer/Common/Manager/WorkbookManagerAbstract.php
index 4732d04..66c186c 100644
--- a/src/Spout/Writer/Common/Manager/WorkbookManagerAbstract.php
+++ b/src/Spout/Writer/Common/Manager/WorkbookManagerAbstract.php
@@ -6,6 +6,7 @@ use Box\Spout\Common\Exception\IOException;
 use Box\Spout\Writer\Common\Helper\FileSystemWithRootFolderHelperInterface;
 use Box\Spout\Writer\Common\Entity\Options;
 use Box\Spout\Writer\Common\Manager\Style\StyleManagerInterface;
+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 0c23f7f..ebfe922 100644
--- a/src/Spout/Writer/Common/Manager/WorkbookManagerInterface.php
+++ b/src/Spout/Writer/Common/Manager/WorkbookManagerInterface.php
@@ -7,7 +7,6 @@ use Box\Spout\Writer\Common\Entity\Sheet;
 use Box\Spout\Writer\Common\Entity\Row;
 use Box\Spout\Writer\Common\Entity\Workbook;
 use Box\Spout\Writer\Common\Entity\Worksheet;
-use Box\Spout\Writer\Common\Sheet;
 use Box\Spout\Writer\Exception\SheetNotFoundException;
 use Box\Spout\Writer\Exception\WriterException;
 
diff --git a/src/Spout/Writer/ODS/Manager/WorksheetManager.php b/src/Spout/Writer/ODS/Manager/WorksheetManager.php
index 5a46254..7b2a242 100644
--- a/src/Spout/Writer/ODS/Manager/WorksheetManager.php
+++ b/src/Spout/Writer/ODS/Manager/WorksheetManager.php
@@ -30,7 +30,7 @@ class WorksheetManager implements WorksheetManagerInterface
 
     /**
      * WorksheetManager constructor.
-     *
+     * @param StyleManager $styleManager
      * @param \Box\Spout\Common\Escaper\ODS $stringsEscaper
      * @param StringHelper $stringHelper
      */
@@ -91,7 +91,6 @@ class WorksheetManager implements WorksheetManagerInterface
         return $tableElement;
     }
 
-    /**
     /**
      * Adds a row to the worksheet.
      *
@@ -116,7 +115,7 @@ class WorksheetManager implements WorksheetManagerInterface
         for ($i = 0; $i < $cellsCount; $i++) {
 
             /** @var Cell $cell */
-            $cell = $row->getCells()[$currentCellIndex];
+            $cell = $cells[$currentCellIndex];
             /** @var Cell|null $nextCell */
             $nextCell = isset($cells[$nextCellIndex]) ? $cells[$nextCellIndex] : null;
 
diff --git a/src/Spout/Writer/WriterAbstract.php b/src/Spout/Writer/WriterAbstract.php
index ecba0db..3a08838 100644
--- a/src/Spout/Writer/WriterAbstract.php
+++ b/src/Spout/Writer/WriterAbstract.php
@@ -344,20 +344,25 @@ abstract class WriterAbstract implements WriterInterface
             throw new InvalidArgumentException('The "$style" argument must be a Style instance and cannot be NULL.');
         }
 
-        $this->addRows(array_map(function ($row) use ($style) {
+        foreach($dataRows as $row) {
+
             if (is_array($row)) {
-                return $this->createRowFromArray($row, $style);
+                $row = $this->createRowFromArray($row, $style);
             } elseif ($row instanceof Row) {
-                return $row;
+                $row->setStyle($style);
             } else {
                 throw new InvalidArgumentException();
             }
-        }, $dataRows));
+
+            $this->addRow($row);
+        }
 
         return $this;
     }
 
     /**
+     * @TODO: Move this into styleMerger
+     *
      * @param Row $row
      * @return $this
      */
@@ -367,9 +372,8 @@ abstract class WriterAbstract implements WriterInterface
         if (null === $defaultRowStyle) {
             return $this;
         }
-        $merged = $this->styleMerger->merge($row->getStyle(), $defaultRowStyle);
-        $row->setStyle($merged);
-        return $this;
+        $mergedStyle = $this->styleMerger->merge($row->getStyle(), $defaultRowStyle);
+        $row->setStyle($mergedStyle);
     }
 
     /**