input: def TicTacToe_Game():
      """ A class to represent a TicTacToe game.
      It initializes a 3x3 board with empty cells represented by '_'. The game
      starts with the 'x' player. The display method prints the current state of 
      the board. The check_win method checks if the current player has won the game.
  
      Example:
      >>> game = TicTacToe()
      >>> game.board
      [['_', '_', '_'], ['_', '_', '_'], ['_', '_', '_']]
      >>> game.turn
      'x'
      """
output:     
      board = [['_' for _ in range(3)] for _ in range(3)]
      turn = 'x'
  
      def display(self):
          for row in self.board:
              print(" ".join(row))
  
      def check_win(self):
          for row in self.board:
              if row[0] == row[1] == row[2] != '_':
                  return True
          for col in range(3):
              if self.board[0][col] == self.board[1][col] == self.board[2][col] != '_':
                  return True
          if self.board[0][0] == self.board[1][1] == self.board[2][2] != '_':
              return True
          if self.board[0][2] == self.board[1][1] == self.board[2][0] != '_':
              return True
          return False
  