input: Write a function to implement the TicTacToe game in Python. The function should include an initialization method to set up an empty 3x3 board and initialize the turn to 'x'. It should also include a method to display the board and a method to check if the current player has won the game. If the current player has a row, column, or diagonal of three 'x's or 'o's, the function should return True, indicating that the current player has won. If not, it should return False.
  class TicTacToe:
  
  def __init__(self):
      self.board = [['_' for _ in range(3)] 
                     for _ in range(3)]
      self.turn = 'x'
      
  def display(self):
      for row in self.board:
          print(' '.join(row))
  
  def check_win(self):
      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
  
  assert not TicTacToe().check_win()
  assert not TicTacToe().check_win()
  assert not TicTacToe().check_win()
  assert not TicTacToe().check_win()
  assert not TicTacToe().check_win()
output: 
  def __init__(self):
      self.board = [['_' for _ in range(3)] for _ in range(3)]
      self.turn = 'x'
      
  def display(self):
      for row in self.board:
          print(' '.join(row))
  
  def check_win(self):
      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
  