code: def signal(self, details):
          
          log = self._params.get('log', self._discard)
          if '_signal' not in dir(self._parent) or not callable(getattr(self._parent, '_signal')):
              log.error("Event parent '%s' has no '_signal' method", self._name)
              return
          sig = utils.signum(self._handler_arg)
          if sig is None:
              log.error("Invalid signal '%s' for task '%s'", self._handler_arg, sig._name)
              return
          log.info("sending %s to all '%s' processes", utils.signame(sig), self._name)
          self._parent._signal(sig)
docs: Send a signal to all task processes.