@Test public void mapT3() { Tuple4<Integer, Integer, String, Integer> base = Tuples.of(100, 200, "Foo", 400); Tuple2<?,?> mapped = base.mapT3(String::length); assertThat(mapped).isNotSameAs(base) .hasSize(4) .containsExactly(base.getT1(), base.getT2(), 3, base.getT4()); }