code: def format_time(
          self,
          hour_expression,
          minute_expression,
          second_expression=''
      ):
          
          hour = int(hour_expression)
  
          period = ''
          if self._options.use_24hour_time_format is False:
              period = " PM" if (hour >= 12) else " AM"
              if hour > 12:
                  hour -= 12
  
          minute = str(int(minute_expression))  # !FIXME WUT ???
          second = ''
          if second_expression is not None and second_expression:
              second = "{}{}".format(":", str(int(second_expression)).zfill(2))
  
          return "{0}:{1}{2}{3}".format(str(hour).zfill(2), minute.zfill(2), second, period)
docs: Given time parts, will contruct a formatted time description
          Args:
              hour_expression: Hours part
              minute_expression: Minutes part
              second_expression: Seconds part
          Returns:
              Formatted time description