try {
      future.get(timeoutMillis, MILLISECONDS);
      shouldThrow();
    } catch (TimeoutException success) {
    } catch (Exception e) {
      threadUnexpectedException(e);
    } finally {
      future.cancel(true);
    }
    assertTrue(millisElapsedSince(startTime) >= timeoutMillis);
  }

  /** Fails with message "should throw exception". */
  public void shouldThrow() {
    fail("Should throw exception");
  }