public static function setConnectionConfig()
	{
		if (!static::$_dbConnectionConfig) {
			$config = static::_getDbConnectionConfig();
			if (!is_array($config) || empty($config))
				throw new \ErrorException(
					'Not set configuration of database in file '
					.APPPATH.'config/database.php. '
					.'See example '.__DIR__.'database.php.config_example'
				);
			static::_setDbConnectionConfig($config);
			static::$_dbConnectionConfig = $config;
		}
	}