code: def __repr__(self):
      dump = ""
      for x in range(self.size[0]):
          for y in range(self.size[1]):
              pos = (x, y)
              if pos == self.start:
                  dump += "\u2b55"
              elif pos == self.goal:
                  dump += "\u2b50"
              elif pos in self.walls:
                  dump += "\u2b1b"
              else:
                  dump += "\u2b1c"
          dump += "\n"
      return dump
  
imports: import logging
  import random
  from typing import Iterable, Optional, Sequence, Tuple
  import numpy
  import torch
  from reagent.ope.estimators.sequential_estimators import DMEstimator, DoublyRobustEstimator, EpsilonGreedyRLPolicy, IPSEstimator, MAGICEstimator, NeuralDualDICE, RewardProbability, RLEstimatorInput, State, StateDistribution, StateReward, ValueFunction
  from reagent.ope.estimators.types import Action, ActionSpace
  from reagent.ope.test.envs import Environment, PolicyLogGenerator
  from reagent.ope.trainers.rl_tabular_trainers import DPTrainer, DPValueFunction, EstimatedStateValueFunction, TabularPolicy
label_desc: Use image node_id 13 for calling the GridWorld obj's underlying member method code with example usage: obj.__repr__() and returns: dump