public function load()
    {
        $output = [];
        $args = func_get_args();
        foreach( $args as $arg ) {
            if( is_array($arg) ) {
                $output = array_merge(
                    call_user_func_array( [$this, 'load'], $arg ),
                    $output
                );
            } else {
                $this->loadHandler($arg);
                $output[] = $arg;
            }
        }
        return $output;
    }