Return type and inheritance bug fixing.

Author: Martin Brecht-Precht

src/Block/BlockInterface.php

@@ -43,9 +43,10 @@ public function onAttach(BlockParentInterface $blockParent);
 	public function onDetach();
 
 	/**
+	 * @noinspection ReturnTypeCanBeDeclaredInspection
 	 * @return BlockParentInterface
 	 */
-	public function getParent(): BlockParentInterface;
+	public function getParent();
 
 	/**
 	 * @param HandlerInterface $markdomHandler

src/Block/ListItemInterface.php

@@ -13,9 +13,10 @@ interface ListItemInterface extends BlockParentInterface
 {
 
 	/**
+	 * @noinspection ReturnTypeCanBeDeclaredInspection
 	 * @return ListBlockInterface
 	 */
-	public function getParent(): ListBlockInterface;
+	public function getParent();
 
 	/**
 	 * @param ListBlockInterface $listBlock

src/Content/ContentInterface.php

@@ -30,9 +30,10 @@ interface ContentInterface extends NodeInterface
 	public function getContentType(): string;
 
 	/**
+	 * @noinspection ReturnTypeCanBeDeclaredInspection
 	 * @return ContentParentInterface
 	 */
-	public function getParent(): ContentParentInterface;
+	public function getParent();
 
 	/**
 	 * @return BlockInterface