return "tryEnterIf";
  }

  private String enterWhen() {
    return interruptible ? "enterWhen" : "enterWhenUninterruptibly";
  }

  private String waitFor() {
    return interruptible ? "waitFor" : "waitForUninterruptibly";
  }

  private String leave() {
    return "leave";
  }

  public final void testMutualExclusion() throws Exception {
    thread1.callAndAssertReturns(enter());