input: Write a python function to check if a TicTacToe game has been won or drawn.
  assert t.is_win('X')==True
  assert t.is_win('O')==False
  assert t.is_draw()==False
output: class TicTacToe:
      def __init__(self, board):
          self.board = board
  
      def is_win(self, player):
          for row in self.board:
              if all([cell == player for cell in row]):
                  return True
          
          for col in range(len(self.board)):
              if all([self.board[row][col] == player for row in range(len(self.board))]):
                  return True
          
          if all([self.board[i][i] == player for i in range(len(self.board))]):
              return True
          
          if all([self.board[i][len(self.board) - 1 - i] == player for i in range(len(self.board))]):
              return True
          
          return False
      
      def is_draw(self):
          if any([' ' in row for row in self.board]):
              return False
          if self.is_win('X') or self.is_win('O'):
              return False
          return True