private function _checkdatabase($database)
    {

        if (count($this->_collection) == 0) {
            $this->_collection[$database] = new $database();

            return $this->_collection[$database];
        }

        $new = false;
        foreach ($this->_collection as $db) {
            if ($db === $database) continue;
            $new = true;
        }

        if ($new === true) {
            $this->_collection[$database] = new $database();
        }

        return false;
    }