@staticmethod
def metadata_updated_on(item):
    """Extracts the update time from a Jenkins item.

        The timestamp is extracted from 'timestamp' 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
        """
    return float(item['timestamp'] / 1000)
