code: def GetMessages(self, formatter_mediator, event):
      
      if self.DATA_TYPE != event.data_type:
        raise errors.WrongFormatter('Unsupported data type: {0:s}.'.format(
            event.data_type))
  
      event_values = event.CopyToDict()
  
      file_reference = event_values.get('file_reference', None)
      if file_reference:
        event_values['file_reference'] = '{0:d}-{1:d}'.format(
            file_reference & 0xffffffffffff, file_reference >> 48)
  
      parent_file_reference = event_values.get('parent_file_reference', None)
      if parent_file_reference:
        event_values['parent_file_reference'] = '{0:d}-{1:d}'.format(
            parent_file_reference & 0xffffffffffff, parent_file_reference >> 48)
  
      update_reason_flags = event_values.get('update_reason_flags', 0)
      update_reasons = []
      for bitmask, description in sorted(self._USN_REASON_FLAGS.items()):
        if bitmask & update_reason_flags:
          update_reasons.append(description)
  
      event_values['update_reason'] = ', '.join(update_reasons)
  
      update_source_flags = event_values.get('update_source_flags', 0)
      update_sources = []
      for bitmask, description in sorted(self._USN_SOURCE_FLAGS.items()):
        if bitmask & update_source_flags:
          update_sources.append(description)
  
      event_values['update_source'] = ', '.join(update_sources)
  
      return self._ConditionalFormatMessages(event_values)
docs: Determines the formatted message strings for an event object.
  
      Args:
        formatter_mediator (FormatterMediator): mediates the interactions
            between formatters and other components, such as storage and Windows
            EventLog resources.
        event (EventObject): event.
  
      Returns:
        tuple(str, str): formatted message string and short message string.
  
      Raises:
        WrongFormatter: if the event object cannot be formatted by the formatter.