protected function _configuration()
    {
        return [
            'default_migration_table' => self::SCHEMA_TABLE,
            'default_database'        => $this->_connectionConfig->get('name'),

            $this->_connectionConfig->get('name') => [
                'adapter'       => $this->_adapterName,
                'version_order' => Config::VERSION_ORDER_CREATION_TIME,
                'host'          => $this->_connectionConfig->get('host'),
                'port'          => $this->_connectionConfig->get('port'),
                'name'          => $this->_connectionConfig->get('database'),
                'user'          => $this->_connectionConfig->get('username'),
                'pass'          => $this->_connectionConfig->get('password'),
                'charset'       => $this->_connectionConfig->get('encoding'),
                'unix_socket'   => $this->_connectionConfig->get('unix_socket')
            ]
        ];
    }