public function hasData($key = null)
    {
        if (!is_null($key)) {
            return isset($this->data[$key]);
        }

        return !empty($this->data);
    }
public function hasData($key = null)
    {
        if (!is_null($key)) {
            return isset($this->data[$key]);
        }

        return !empty($this->data);
    }
public function hasData ( $ key = null ) { if ( ! is_null ( $ key ) ) { return isset ( $ this -> data [ $ key ] ) ; } return ! empty ( $ this -> data ) ; }
Returns whether the notification has data, optionally for the given key.

@param string $key

@return bool
Returns whether the notification has data optionally for the given key .