code: def remove_update_callback(self, group, name=None, cb=None):
          
          if not cb:
              return
  
          if not name:
              if group in self.group_update_callbacks:
                  self.group_update_callbacks[group].remove_callback(cb)
          else:
              paramname = '{}.{}'.format(group, name)
              if paramname in self.param_update_callbacks:
                  self.param_update_callbacks[paramname].remove_callback(cb)
docs: Remove the supplied callback for a group or a group.name