def build_combinations
      @round += 1
      ExperimentCombinations.new(
        round: @round,
        occurrences_count: search_cases.size,
        ok_experiments: @ok_experiments,
        fail_experiments: @fail_experiments
      ).generate_combinations
    end
def build_combinations
      @round += 1
      ExperimentCombinations.new(
        round: @round,
        occurrences_count: search_cases.size,
        ok_experiments: @ok_experiments,
        fail_experiments: @fail_experiments
      ).generate_combinations
    end
Increase the `@round` by 1 to {ExperimentCombinations#generate_combinations}.