InternalFunctors { @SuppressWarnings("unchecked") static <T, B> BiFunction<T, B, T> firstOfTwo() { return FIRST_OF_TWO; }    }
@Test public void testFirstOfTwo() { BiFunction<String, Integer, String> map = InternalFunctors.firstOfTwo(); assertEquals("followedBy", map.toString()); assertEquals("one", map.apply("one", 2)); }