@Test public void mapT2() { Tuple4<Integer, String, Integer, Integer> base = Tuples.of(100, "Foo", 300, 400); Tuple2<?,?> mapped = base.mapT2(String::length); assertThat(mapped).isNotSameAs(base) .hasSize(4) .containsExactly(base.getT1(), 3, base.getT3(), base.getT4()); }