// Pause in step 2.
    step2Waiter.awaitStarted();

    // Everything should still be open.
    assertStillOpen(closeable1, closeable2, closeable3, closeable4);

    // Cancel step 3, resume step 2, and pause in step 4.
    assertWithMessage("step3.cancel()").that(step3.cancel(false)).isTrue();
    step2Waiter.awaitReturned();
    step4Waiter.awaitStarted();

    // Step 1 is not cancelled because it was done.