input: Write a function to create and initialize a BoardGame instance with a given number of players.
  assert isinstance(create_board_game(4), BoardGame)
  assert create_board_game(3).numPlayers == 3
  assert create_board_game(5).tokens == {}
output: def create_board_game(num_players):
      class BoardGame:
          def __init__(self, numPlayers):
              self.numPlayers = numPlayers
              self.tokens = {}
      
      return BoardGame(num_players)