Merge branch '4.4' into 5.2

* 4.4:
  [4.4] Add missing `@return` annotations
  Handle lock with long key

Adapter/TagAwareAdapter.php

@@ -314,6 +314,9 @@ class TagAwareAdapter implements TagAwareAdapterInterface, TagAwareCacheInterfac
         return $this->invalidateTags([]);
     }
 
+    /**
+     * @return array
+     */
     public function __sleep()
     {
         throw new \BadMethodCallException('Cannot serialize '.__CLASS__);

DoctrineProvider.php

@@ -48,6 +48,8 @@ class DoctrineProvider extends CacheProvider implements PruneableInterface, Rese
 
     /**
      * {@inheritdoc}
+     *
+     * @return mixed
      */
     protected function doFetch($id)
     {

Traits/AbstractAdapterTrait.php

@@ -315,6 +315,9 @@ trait AbstractAdapterTrait
         $this->ids = [];
     }
 
+    /**
+     * @return array
+     */
     public function __sleep()
     {
         throw new \BadMethodCallException('Cannot serialize '.__CLASS__);