def log(severity, message, tid)
      now = Time.now
      ss = ['DEBUG', 'INFO', 'WARN', 'ERROR', 'FATAL'][severity]
      ss = '' if ss.nil?
      if @formatter.nil?
        msg = "#{ss[0]}, [#{now.strftime('%Y-%m-%dT%H:%M:%S.%6N')} ##{tid}]  #{ss} -- : #{message}\n"
      else
        msg = @formatter.call(ss, now, tid, message)
      end
      @logger.add(severity, msg)
      @forward.log(severity, message, tid) unless @forward.nil?
    end
def log(severity, message, tid)
      now = Time.now
      ss = ['DEBUG', 'INFO', 'WARN', 'ERROR', 'FATAL'][severity]
      ss = '' if ss.nil?
      if @formatter.nil?
        msg = "#{ss[0]}, [#{now.strftime('%Y-%m-%dT%H:%M:%S.%6N')} ##{tid}]  #{ss} -- : #{message}\n"
      else
        msg = @formatter.call(ss, now, tid, message)
      end
      @logger.add(severity, msg)
      @forward.log(severity, message, tid) unless @forward.nil?
    end
Writes a message if the severity is high enough. This method is
 executed asynchronously.
 @param [Fixnum] severity one of the Logger levels
 @param [String] message string to log
 @param [Fixnum|String] tid thread id of the thread generating the message