code: def update(self, back=None):
          '''
          Update all of the enabled fileserver backends which support the update
          function, or
          '''
          back = self.backends(back)
          for fsb in back:
              fstr = '{0}.update'.format(fsb)
              if fstr in self.servers:
                  log.debug('Updating %s fileserver cache', fsb)
                  self.servers[fstr](f update(self, back=None):
          '''
          Update all of the enabled fileserver backends which support the update
          function, or
          '''
          back = self.backends(back)
          for fsb in back:
              fstr = '{0}.update'.format(fsb)
              if fstr in self.servers:
                  log.debug('Updating %s fileserver cache', fsb)
                  self.servers[fstr]()
docs: Update all of the enabled fileserver backends which support the update
          function, or