@staticmethod<EOL><INDENT>def metadata_updated_on(item):<DEDENT>
return float(item['<STR_LIT>'])<EOL>
Extracts and converts the update time from a Gerrit item.

        The timestamp is extracted from 'lastUpdated' field. This date is
        a UNIX timestamp but needs to be converted to a float value.

        :param item: item generated by the backend

        :returns: a UNIX timestamp