Support XLSX that don't have a sharedStrings.xml file

tests/Spout/Reader/XLSXTest.php

@@ -100,6 +100,20 @@ class XLSXTest extends \PHPUnit_Framework_TestCase
         }
     }
 
+    /**
+     * @return void
+     */
+    public function testReadShouldSupportFilesWithoutSharedStringsFile()
+    {
+        $allRows = $this->getAllRowsForFile('sheet_with_no_shared_strings_file.xlsx');
+
+        $expectedRows = [
+            [10, 11],
+            [20, 21],
+        ];
+        $this->assertEquals($expectedRows, $allRows);
+    }
+
     /**
      * @return void
      */