input: 
  class TicTacToe:
  
      def __init__(self):
          self.board = [['_' for _ in range(3)] 
                        for _ in range(3)]
          self.turn = 'x'
  
      def display(self):
          """ Display the current state of the TicTacToe board.
          >>> game = TicTacToe()
          >>> game.display()
          _ _ _
          _ _ _
          _ _ _
          """
          for row in self.board:
              print(' '.join(row))
  
      def check_win(self):
          """ Check if the current player has won the game.
          >>> game = TicTacToe()
          >>> game.turn = 'x'
          >>> game.board = [['x', 'x', 'x'], ['_', '_', '_'], ['_', '_', '_']]
          >>> game.check_win()
          True
          """
          board = self.board
  
          # check if the player with the current turn has a row of three
          for row in self.board:
              if row.count(self.turn) == 3:
                  return True
              
          # check if the player with the current turn has a column of three
          for col in range(3):
              if board[0][col] == board[1][col] and board[1][col] == board[2][col] and board[2][col] == self.turn:
                  return True
              
          # check for the two diagonals
          if board[0][0] == board[1][1] and board[1][1] == board[2][2] and board[2][2] == self.turn:
              return True
          if board[0][2] == board[1][1] and board[1][1] == board[2][0] and board[2][0] == self.turn:
              return True
          return False
  
output:     def make_move(self, row: int, col: int):
          """ Make a move on the board.
          >>> game = TicTacToe()
          >>> game.make_move(0, 0)
          >>> game.display()
          x _ _
          _ _ _
          _ _ _
          >>> game.make_move(1, 1)
          >>> game.display()
          x _ _
          _ o _
          _ _ _
          """
          if self.board[row][col] == '_':
              self.board[row][col] = self.turn
              self.turn = 'o' if self.turn == 'x' else 'x'
          else:
              print("Invalid move, try again.")
  
      def is_full(self):
          """ Check if the board is full.
          >>> game = TicTacToe()
          >>> game.board = [['x', 'o', 'x'], ['x', 'o', 'o'], ['o', 'x', 'x']]
          >>> game.is_full()
          True
          """
          return all(cell != '_' for row in self.board for cell in row)