private void assertTestRuns(int... failingIndices) {
   IntByRef counter = new IntByRef();
   TestResult result =
       new TestResult() {
         @Override
         public void testStarted(Test test) {
           super.testStarted(test);
           Assert.isInstanceOf(CountingTest.class, test);
         }
       };
   new TestRunner(Iterators.iterable(new SimpleTestSuite(counter, NUM_TESTS, failingIndices)))
       .run(result);
   Assert.areEqual(NUM_TESTS, result.testCount());
   Assert.areEqual(failingIndices.length, result.failures().size());
   Assert.areEqual(NUM_TESTS + 2, counter.value);
 }