[CS] Enforces null type hint on last position in phpDocs

Author: carusogabriel

Node/ElementNode.php

@@ -37,15 +37,15 @@ public function __construct($namespace = null, $element = null)
     }
 
     /**
-     * @return null|string
+     * @return string|null
      */
     public function getNamespace()
     {
         return $this->namespace;
     }
 
     /**
-     * @return null|string
+     * @return string|null
      */
     public function getElement()
     {

Node/SelectorNode.php

@@ -28,7 +28,7 @@ class SelectorNode extends AbstractNode
 
     /**
      * @param NodeInterface $tree
-     * @param null|string   $pseudoElement
+     * @param string|null   $pseudoElement
      */
     public function __construct(NodeInterface $tree, $pseudoElement = null)
     {
@@ -45,7 +45,7 @@ public function getTree()
     }
 
     /**
-     * @return null|string
+     * @return string|null
      */
     public function getPseudoElement()
     {

Parser/TokenStream.php

@@ -142,7 +142,7 @@ public function getNextIdentifier()
     /**
      * Returns nex identifier or star delimiter token.
      *
-     * @return null|string The identifier token value or null if star found
+     * @return string|null The identifier token value or null if star found
      *
      * @throws SyntaxErrorException If next token is not an identifier or a star delimiter
      */