@staticmethod<EOL><INDENT>def metadata_updated_on(item):<DEDENT>
ts = item['<STR_LIT>']<EOL>ts = str_to_datetime(ts)<EOL>return ts.timestamp()<EOL>
Extracts the update time from a Bugzilla item.

        The timestamp used is extracted from 'last_change_time' field.
        This date is converted to UNIX timestamp format taking into
        account the timezone of the date.

        :param item: item generated by the backend

        :returns: a UNIX timestamp