code: def clear(self):
          '''Clear a chessboard'''
          self.pos = [[0 for _ in range(self.board_size)] for _ in range(self.board_size)]
          self.graph = copy.deepcopy(self.pos)
          self._game_round = f clear(self):
          '''Clear a chessboard'''
          self.pos = [[0 for _ in range(self.board_size)] for _ in range(self.board_size)]
          self.graph = copy.deepcopy(self.pos)
          self._game_round = 1
docs: Clear a chessboard