RxJava: Observable to Single

EmptyObservableToSingle.java

	@Test
	public void testEmptyObservableToSingle() {
		Observable.empty()
				.flatMapSingle(o -> Single.just("result"))
				.test()
				.assertValueCount(0)
				.assertNoErrors();
		//Should there be an error?
	}

EmptyObservableToSingleExplanation.java

	@Test
	public void testEmptyObservableToSingleExplanation() {
		Observable.just("item1", "item2")
				.flatMapSingle(o -> Single.just("result"))
				.test()
				.assertValueCount(2)
				.assertValues("result", "result")
				.assertNoErrors();
	}

ObservableToSingle.java

	@Test
	public void testObservableToSingle() {
		Observable.just("item1", "item2")
				.single("result")
				.test()
				.assertError(IllegalArgumentException.class)
				.assertErrorMessage("Sequence contains more than one element!");
	}