### Question:
TilesetPresenter extends MvpPresenter<TilesetUi> { public void selectRegion(TextureRegion region) { this.currentRegion = region; regionSubject.onNext(region); } TilesetPresenter(TilesetPlugin plugin, TilesetManager manager); void loadTileset(FileHandle file); void createPalette(); void createPalette(String name); void selectTileset(Tileset tileset); void tileWidthChanged(int width); void tileHeightChanged(int height); void automapChanged(boolean checked); void selectRegion(TextureRegion region); PublishSubject<Boolean> getAutomapSubject(); PublishSubject<TextureRegion> getRegionSubject(); void levelLoaded(); TextureRegion getCurrentRegion();  }### Answer:
@Test public void testSelectRegion() { TextureRegion region = mock(TextureRegion.class); TestObserver<TextureRegion> test = presenter.getRegionSubject().test(); presenter.selectRegion(region); test.assertValue(region); }