def check_rounds
      round = Hash.new
      round_last = last_round
      @player.values.each do |p|
        p.results.each do |r|
          round[r.round] = true
        end
      end
      (1..round_last).each { |r| raise "there are no results for round #{r}" unless round[r] }
      if rounds
        raise "declared number of rounds is #{rounds} but there are results in later rounds, such as #{round_last}" if rounds < round_last
        raise "declared number of rounds is #{rounds} but there are no results with rounds greater than #{round_last}" if rounds > round_last
      else
        self.rounds = round_last
      end
    end
def check_rounds
      round = Hash.new
      round_last = last_round
      @player.values.each do |p|
        p.results.each do |r|
          round[r.round] = true
        end
      end
      (1..round_last).each { |r| raise "there are no results for round #{r}" unless round[r] }
      if rounds
        raise "declared number of rounds is #{rounds} but there are results in later rounds, such as #{round_last}" if rounds < round_last
        raise "declared number of rounds is #{rounds} but there are no results with rounds greater than #{round_last}" if rounds > round_last
      else
        self.rounds = round_last
      end
    end
Round should go from 1 to a maximum, there should be at least one result in every round and,
 if the number of rounds has been set, it should agree with the largest round from the results.