code: def percept(self, agent):
          "By default, agent perceives things within a default radius."
          return [self.thing_percept(thing, agent)
                  for thing in self.things_near(agent.location)f percept(self, agent):
          "By default, agent perceives things within a default radius."
          return [self.thing_percept(thing, agent)
                  for thing in self.things_near(agent.location)]
docs: By default, agent perceives things within a default radius.