Fix type hints in src/WaterPipe/WaterPipe.php

Co-authored-by: Nana Axel <[email protected]>

Author: manitra

src/WaterPipe/WaterPipe.php

@@ -444,6 +444,7 @@ public function run()
      * If an exception has occured while running the pipe
      * This method will return that exception.
      * Otherwise, will return null.
+     * @return \Exception
      */
     function getRunningException () {
         return $this->_runningException;