code: def test_winner(self):
      board = deepchem.rl.envs.tictactoe.TicTacToeEnvironment()
      X = deepchem.rl.envs.tictactoe.TicTacToeEnvironment.X
      board.state[0][0][0] = X
      board.state[0][0][1] = X
      assert not board.check_winner(X)
      board.state[0][0][2] = X
      assert board.check_winner(X)
  
file_path: deepchem/deepchem/rl/envs/test_tictactoe.py
imports: from unittest import TestCase
  import numpy
  import deepchem.rl.envs.tictactoe
label_desc: Use image node_id 3 for calling the TestTicTacToeEnvironment obj's underlying member method code with example usage: obj.test_winner() without return types