Pair { public Pair(S first, T second) { this.first = first; this.second = second; } Pair(S first, T second); static DRes<Pair<S, T>> lazy(S first, T second); S getFirst(); T getSecond(); @Override boolean equals(Object obj); @Override String toString(); @Override int hashCode();  }
@Test public void testPair() { Pair<String, Integer> pair = new Pair<>("Test", 5); assertEquals("Test", pair.getFirst()); assertEquals(5, pair.getSecond().intValue()); }