docs: def format(self, record):
          ''' Log color formatting. '''
          levelname = record.levelname
          if levelname == 'CRITICAL':
              levelname = record.levelname = 'FATAL'
          record.asctime = self.formatTime(record, self.datefmt)
  
          # render the message part with arguments
          try:  # Allow {} style - need a faster way to determine this:
              message = record.getMessage()
          except TypeError:
              message = record.msg.format(*record.args)
          record.message = message
  
          fields = self._fields
          data = { name: getattr(record, name) for name in fields }
          if 'asctime' in fields and 'msecs' in fields:  # needs option for this
              data['asctime'] += '.{:03.0f}'.format(data.pop('msecs'))
          s = self.dumps(data)
          if self._highlight:
              s = self._highlight(s, get_lexer_by_name('JSON'), _term_formatter,
                                  ).rstrip()
  
          # this needs to be here, Formatter class isn't very extensible.
          if record.exc_info:
              # Cache the traceback text to avoid converting it multiple times
              # (it's constant anyway)
              if not record.exc_text:
                  record.exc_text = self.formatException(record.exc_info)
          if record.exc_text:
              if s[-1:] != "\n":
                  s = s + "\n"
              s = s + record.exc_text
          if record.stack_info:
              if s[-1:] != "\n":
                  s = s + "\n"
              s = s + self.formatStack(record.stack_info)
          return s