[feature] finally return Closure added

Author: Lysice

src/Lock.php

@@ -55,10 +55,11 @@ abstract protected function getCurrentOwner();
 
     /**
      * Attempt to acquire the lock
-     * @param null $callback
+     * @param null|\Closure $callback
+     * @param null|\Closure $finally
      * @return bool|mixed
      */
-    public function get($callback = null)
+    public function get($callback = null, $finally = null)
     {
         $result = $this->acquire();
         if($result && is_callable($callback)) {
@@ -68,6 +69,9 @@ public function get($callback = null)
                 $this->release();
             }
         }
+        if (!$result && is_callable($finally)) {
+            return $finally();
+        }
 
         return $result;
     }