default <T> Collection<Future<T>> inParallel(RunnableWithException runnable, int count) {
    ArrayList<Future<T>> futures = new ArrayList<>(count);
    for (; count > 0; count--) {
      futures.add(inParallel(runnable));
    }
    return futures;
  }
Executor that executes multiple tasks in parallel as part of the main body of concurrent test.

See {@link ConcurrentTestRunner}
geode-concurrency-test/src/main/java/org/apache/geode/test/concurrency/ParallelExecutor.java