Update to Drupal 8.2.6. For more information, see https://www.drupal.org/project/drupal/releases/8.2.6

vendor/symfony/css-selector/XPath/Translator.php

@@ -70,9 +70,6 @@ class Translator implements TranslatorInterface
      */
     private $attributeMatchingTranslators = array();
 
-    /**
-     * Constructor.
-     */
     public function __construct(ParserInterface $parser = null)
     {
         $this->mainParser = $parser ?: new Parser();
@@ -149,7 +146,7 @@ class Translator implements TranslatorInterface
      *
      * @param Extension\ExtensionInterface $extension
      *
-     * @return Translator
+     * @return $this
      */
     public function registerExtension(Extension\ExtensionInterface $extension)
     {
@@ -185,7 +182,7 @@ class Translator implements TranslatorInterface
      *
      * @param ParserInterface $shortcut
      *
-     * @return Translator
+     * @return $this
      */
     public function registerParserShortcut(ParserInterface $shortcut)
     {
@@ -268,9 +265,9 @@ class Translator implements TranslatorInterface
      * @param string    $attribute
      * @param string    $value
      *
-     * @throws ExpressionErrorException
-     *
      * @return XPathExpr
+     *
+     * @throws ExpressionErrorException
      */
     public function addAttributeMatching(XPathExpr $xpath, $operator, $attribute, $value)
     {