sclass TestResults extends TestResult {
  new L<TestResult> results;
  double scoreSum;
  
  void add(TestResult r) {
    scoreSum += r.okPercentage;
    results.add(r);
    okPercentage = doubleRatio(scoreSum, l(results));
  }
  
  toString {
    S s = super.toString() + " (" + n2(results, "test") + ")";
    TestResult worst = lowestByField(results, 'okPercentage);
    if (worst != null) s += "\n  Worst result: " + worst;
    ret s;
  }
}