def add_player(player)
      raise "invalid player" unless player.class == ICU::Player
      raise "player number (#{player.num}) should be unique" if @player[player.num]
      @player[player.num] = player
    end
def add_player(player)
      raise "invalid player" unless player.class == ICU::Player
      raise "player number (#{player.num}) should be unique" if @player[player.num]
      @player[player.num] = player
    end
Add a new player to the tournament. Must have a unique player number.