code: def _update_hook(self, my_task):
          
          if my_task._is_predicted():
              self._predict(my_task)
          LOG.debug("'%s'._update_hook says parent (%s, state=%s) "
                    "is_finished=%s" % (self.name, my_task.parent.get_name(),
                                        my_task.parent.get_state_name(),
                                        my_task.parent._is_finished()))
          if not my_task.parent._is_finished():
              return
          self.entered_event.emit(my_task.workflow, my_task)
          my_task._ready()
docs: Typically this method should perform the following actions::
  
              - Update the state of the corresponding task.
              - Update the predictions for its successors.
  
          Returning non-False will cause the task to go into READY.
          Returning any other value will cause no action.