monitor.leave();
    thread1.assertPriorCallReturns(enterWhen());
  }

  public final void testEnterWhen_alreadyOccupied() throws Exception {
    TestGuard guard = new TestGuard(true);
    thread2.callAndAssertReturns(enter());
    thread1.callAndAssertBlocks(enterWhen(), guard);
    thread2.callAndAssertReturns(leave());
    thread1.assertPriorCallReturns(enterWhen());
  }

   * normally.
   */
  public void assertPriorCallReturns(@Nullable String methodName) throws Exception {
    assertEquals(null, getResponse(methodName).getResult());
  }

  /**
   * Asserts that a prior call that had caused this thread to block or wait has since returned the
   * expected boolean value.
   */
  public void assertPriorCallReturns(boolean expected, @Nullable String methodName)

   * normally.
   */
  public void assertPriorCallReturns(@Nullable String methodName) throws Exception {
    assertEquals(null, getResponse(methodName).getResult());
  }

  /**
   * Asserts that a prior call that had caused this thread to block or wait has since returned the
   * expected boolean value.
   */
  public void assertPriorCallReturns(boolean expected, @Nullable String methodName)