Bugs in passable check in _is_valid() method of Maze object

It seems that negative or out of edge position will result index error in _is_valid() method, because of the passable check. I think it should be changed to def _is_valid(self, position): nonnegative = position[0] >= 0 and position[1] >= 0 within_edge = position[0] < self.maze.size[0] and position[1] < self.maze.size[1] if (nonnegative and within_edge): passable = not self.maze.to_impassable()[position[0]][position[1]] else: passable = False return nonnegative and within_edge and passable

---

IndexError Traceback (most recent call last) in 35 action = agent.act(state, epsilon) 36 ---> 37 _, reward, done, _ = env.step(action) 38 next_state = env.unwrapped.maze.objects.agent.positions[0] 39

//anaconda3/lib/python3.7/site-packages/gym/wrappers/time_limit.py in step(self, action) 14 def step(self, action): 15 assert self._elapsed_steps is not None, "Cannot call env.step() before calling reset()" ---> 16 observation, reward, done, info = self.env.step(action) 17 self._elapsed_steps += 1 18 if self._elapsed_steps >= self._max_episode_steps:

in step(self, action) 21 current_position = self.maze.objects.agent.positions[0] 22 new_position = [current_position[0] + motion[0], current_position[1] + motion[1]] ---> 23 valid = self._is_valid(new_position) 24 if valid: 25 self.maze.objects.agent.positions = [new_position]

in _is_valid(self, position) 44 nonnegative = position[0] >= 0 and position[1] >= 0 45 within_edge = position[0] < self.maze.size[0] and position[1] < self.maze.size[1] ---> 46 passable = not self.maze.to_impassable()[position[0]][position[1]] 47 return nonnegative and within_edge and passable 48

IndexError: index 6 is out of bounds for axis 0 with size 6