Merge pull request #1712 from fmasa/fix/return-types

Added return type

Author: troosan

src/PhpWord/Element/AbstractElement.php

@@ -96,7 +96,7 @@ abstract class AbstractElement
     /**
      * A reference to the parent
      *
-     * @var \PhpOffice\PhpWord\Element\AbstractElement
+     * @var AbstractElement|null
      */
     private $parent;
 
@@ -335,6 +335,11 @@ public function setCommentRangeEnd(Comment $value)
         $this->commentRangeEnd->setEndElement($this);
     }
 
+    /**
+     * Get parent element
+     *
+     * @return AbstractElement|null
+     */
     public function getParent()
     {
         return $this->parent;