this.expectedCompletionWaitMillis = expectedCompletionWaitMillis;
      stopwatch = Stopwatch.createStarted();
    }

    /**
     * Asserts that the expected completion time has passed (and not "too much" time beyond that).
     */
    void assertCompletionExpected() {
      assertAtLeastTimePassed(stopwatch, expectedCompletionWaitMillis);
      assertTimeNotPassed(stopwatch, expectedCompletionWaitMillis + LONG_DELAY_MS);
    }

      this.expectedCompletionWaitMillis = expectedCompletionWaitMillis;
      stopwatch = Stopwatch.createStarted();
    }

    /**
     * Asserts that the expected completion time has passed (and not "too much" time beyond that).
     */
    void assertCompletionExpected() {
      assertAtLeastTimePassed(stopwatch, expectedCompletionWaitMillis);
      assertTimeNotPassed(stopwatch, expectedCompletionWaitMillis + LONG_DELAY_MS);
    }