Granada\ORM::_join_if_not_empty PHP Method

    protected function _join_if_not_empty($glue, $pieces)
    {
        $filtered_pieces = array();
        foreach ($pieces as $piece) {
            if (is_string($piece)) {
                $piece = trim($piece);
            }
            if (!empty($piece)) {
                $filtered_pieces[] = $piece;
            }
        }
        return join($glue, $filtered_pieces);
    }