code: def remove_callback(self, name, fn, *args, **kwargs):
          
          try:
              tup = (fn, args, kwargs)
              if tup in self.cb[name]:
                  self.cb[name].remove(tup)
          except KeyError:
              raise CallbackError("No callback category of '%s'" % (
                  name))
docs: Remove a specific callback that was added.