def set_common_fields(self, warc_type: str, content_type: str):
        '''Set the required fields for the record.'''
        self.fields[self.WARC_TYPE] = warc_type
        self.fields[self.CONTENT_TYPE] = content_type
        self.fields[self.WARC_DATE] = wpull.util.datetime_str()
        self.fields[self.WARC_RECORD_ID] = '<{0}>'.format(uuid.uuid4().urn)
Set the required fields for the record.