@staticmethod<EOL><INDENT>def metadata_updated_on(item):<DEDENT>
ts = item['<STR_LIT>'][<NUM_LIT:0>]['<STR_LIT>']<EOL>ts = str_to_datetime(ts)<EOL>ts = ts.replace(tzinfo=dateutil.tz.tzutc())<EOL>return ts.timestamp()<EOL>
Extracts and coverts the update time from a Bugzilla item.

        The timestamp is extracted from 'delta_ts' field. This date is
        converted to UNIX timestamp format. Due Bugzilla servers ignore
        the timezone on HTTP requests, it will be ignored during the
        conversion, too.

        :param item: item generated by the backend

        :returns: a UNIX timestamp