public static void stopSenderInVMsAsync(String senderId, VM... vms) {
    List<AsyncInvocation<Void>> tasks = new LinkedList<>();
    for (VM vm : vms) {
      tasks.add(vm.invokeAsync(() -> stopSender(senderId)));
    }
    for (AsyncInvocation<Void> invocation : tasks) {
      try {
        invocation.await();
      } catch (InterruptedException e) {
        fail("Stopping senders was interrupted");
      }
    }
  }
Returns a Map that contains the count for number of cache server and number of Receivers.
geode-wan/src/distributedTest/java/org/apache/geode/internal/cache/wan/WANTestBase.java