awaitBlockedOnInstanceOf(runner, InterruptibleTask.Blocker.class);

    Blocker blocker = (Blocker) LockSupport.getBlocker(runner);
    Thread owner = blocker.getOwner();
    assertThat(owner).isSameInstanceAs(interrupter);

    slowChannel.exitClose.countDown(); // release the interrupter

    @Override
    public void run() {}

    private void setOwner(Thread thread) {
      super.setExclusiveOwnerThread(thread);
    }

    @VisibleForTesting
    @CheckForNull
    Thread getOwner() {
      return super.getExclusiveOwnerThread();
    }

    @Override
    public String toString() {
      return task.toString();
    }
  }

  @Override
  public final String toString() {

    @Override
    public void run() {}

    private void setOwner(Thread thread) {
      super.setExclusiveOwnerThread(thread);
    }

    @VisibleForTesting
    @CheckForNull
    Thread getOwner() {
      return super.getExclusiveOwnerThread();
    }

    @Override
    public String toString() {
      return task.toString();
    }
  }

  @Override
  public final String toString() {