isInterruptibleRegistered.await();
    RuntimeException expected = assertThrows(RuntimeException.class, () -> task.interruptTask());
    assertThat(expected)
        .hasMessageThat()
        .isEqualTo("I bet you didn't think Thread.interrupt could throw");
    // We need to wait for the runner to exit.  It used to be that the runner would get stuck in the
    // busy loop when interrupt threw.
    runner.join(SECONDS.toMillis(10));
  }