### Question:
ReceptorActor extends TileableActor<Receptor> implements ReceptorListener { @Override public void ballDisposed(Tileable tileable, Direction direction, Marble marble) { Actor actor = getContext().actor(marble); if (actor != null) { actor.remove(); } } ReceptorActor(Receptor receptor, ActorContext context); @Override TextureRegion getTileTexture(); @Override void draw(Batch batch, float parentAlpha); @Override void act(float deltaTime); @Override void receptorMarked(Receptor receptor); @Override void receptorAssigned(Receptor receptor); @Override void ballDisposed(Tileable tileable, Direction direction, Marble marble); @Override void ballAccepted(Tileable tileable, Direction direction, Marble marble);  }### Answer:
@Test public void disposeUnknown() throws Exception { assertThat(latch.await(5, TimeUnit.SECONDS)).isTrue(); assertThatCode(() -> actor.ballDisposed(receptor, Direction.LEFT, new Marble(MarbleType.BLUE)) ).doesNotThrowAnyException(); }