'Calls the Update() method of a given VFSFile/VFSDirectory object.'

@flow.StateHandler()
def Start(self):

    self.Init()
    fd = aff4.FACTORY.Open(self.args.vfs_file_urn, mode='rw', token=self.token)
    if (fd.Get(fd.Schema.TYPE) is None):
        fd = fd.Upgrade(standard.VFSDirectory)
    self.state.get_file_flow_urn = fd.Update(attribute=self.args.attribute, priority=rdf_flows.GrrMessage.Priority.HIGH_PRIORITY)
