int[] successCalls = new int[1];
    int[] failureCalls = new int[1];
    FutureCallback<String> callback =
        new FutureCallback<String>() {
          @Override
          public void onSuccess(String result) {
            successCalls[0]++;
            throw exception;
          }

          @Override
          public void onFailure(Throwable t) {
            failureCalls[0]++;
          }
        };

    int[] successCalls = new int[1];
    int[] failureCalls = new int[1];
    FutureCallback<String> callback =
        new FutureCallback<String>() {
          @Override
          public void onSuccess(String result) {
            successCalls[0]++;
            throw exception;
          }

          @Override
          public void onFailure(Throwable t) {
            failureCalls[0]++;
          }
        };