protected function _quoteJoins($joins)
    {
        $result = [];
        foreach ($joins as $value) {
            $alias = null;
            if (!empty($value['alias'])) {
                $alias = $this->_driver->quoteIdentifier($value['alias']);
                $value['alias'] = $alias;
            }

            if (is_string($value['table'])) {
                $value['table'] = $this->_driver->quoteIdentifier($value['table']);
            }

            $result[$alias] = $value;
        }

        return $result;
    }