public function __tostring ()
    {
        if (is_null($this->queryElements))
        {
            return "";
        }

        $query = [];

        foreach ($this->queryElements as $soqlKey => $value)
        {
            $value = (is_array($value)) ? implode(self::DELIMITER, $value) : $value;

            $query[] = sprintf("%s=%s", $soqlKey, $value);
        }

        return implode("&", $query);
    }