code: def test_frozenlake_dfs_map_generation(map_size: int):
      """Frozenlake has the ability to generate random maps.
  
      This function checks that the random maps will always be possible to solve for sizes 5, 10, 16,
      currently only 8x8 maps can be generated.
      """
      new_frozenlake = generate_random_map(map_size)
      assert len(new_frozenlake) == map_size
      assert len(new_frozenlake[0]) == map_size
  
      # Runs a depth first search through the map to find the path.
      directions = [(1, 0), (0, 1), (-1, 0), (0, -1)]
      frontier, discovered = [], set()
      frontier.append((0, 0))
      while frontier:
          row, col = frontier.pop()
          if (row, col) not in discovered:
              discovered.add((row, col))
  
              for row_direction, col_direction in directions:
                  new_row = row + row_direction
                  new_col = col + col_direction
                  if (
                      0 <= new_row < map_size
                      and 0 <= new_col < map_size
                  ):
                      if new_frozenlake[new_row][new_col] == "G":
                          return  # Successful, a route through the map was found
                      if new_frozenlake[new_row][new_col] not in "#H":
                          frontier.append((new_row, new_col))
      raise AssertionError("No path through the frozenlake was found.")
  
file_path: gym/tests/envs/test_env_implementation.py
imports: from typing import Optional
  import numpy
  import pytest
  import gym
  from gym.envs.box2d import BipedalWalker
  from gym.envs.box2d.lunar_lander import demo_heuristic_lander
  from gym.envs.toy_text import TaxiEnv
  from gym.envs.toy_text.frozen_lake import generate_random_map
label_desc: Use image node_id 4 for calling a global function with example usage: test_frozenlake_dfs_map_generation(map_size) without return types