protected function removeObserversByCallback(callable $callback): EventInterface
    {
        //find the callback
        foreach ($this->observers as $event => $observer) {
            $this->removeObserversByEvent($event, $callback);
        }

        return $this;
    }
protected function removeObserversByCallback(callable $callback): EventInterface
    {
        //find the callback
        foreach ($this->observers as $event => $observer) {
            $this->removeObserversByEvent($event, $callback);
        }

        return $this;
    }
protected function removeObserversByCallback ( callable $ callback ) : EventInterface { //find the callback foreach ( $ this -> observers as $ event => $ observer ) { $ this -> removeObserversByEvent ( $ event , $ callback ) ; } return $ this ; }
Removes all observers matching this callback

@param *callable $callback

@return EventInterface
Removes all observers matching this callback