@VisibleForTesting
  int getSleepDuration() {
    return sleepDuration;
  }
@Test
  public void testNoMetricUpdatesThenNoWaiting() {
    ClientThrottlingAnalyzer analyzer = new ClientThrottlingAnalyzer(
        "test",
        ANALYSIS_PERIOD);
    validate(0, analyzer.getSleepDuration());
    sleep(ANALYSIS_PERIOD_PLUS_10_PERCENT);
    validate(0, analyzer.getSleepDuration());
  }