code: private static function _initLogFile()
      {
          self::$_sFileLog = str_replace(DIRECTORY_SEPARATOR.'kernel'.DIRECTORY_SEPARATOR.'lib', '', __DIR__).DIRECTORY_SEPARATOR.
              "data".DIRECTORY_SEPARATOR."log".DIRECTORY_SEPARATOR."php-error.log";
  
          ini_set("log_errors", 1);
          ini_set("error_log", self::$_sFileLog);
  
          if (file_exists(self::$_sFileLog) === false) { file_put_contents(self::$_sFileLog, ''); }
      }
docs: init the log file (error_log)
  
  @access private
  @return void