return null;
          }
        });

    assertEquals(numberOfThreads * 2, ticker.read());
  }

  @GwtIncompatible // concurrency

  public void testConcurrentAutoIncrementStep() throws Exception {
    int incrementByNanos = 3;
    FakeTicker ticker = new FakeTicker().setAutoIncrementStep(incrementByNanos, NANOSECONDS);

    int numberOfThreads = 64;
    runConcurrentTest(