### Question:
ImmutablePair { public A getFirst() { return first; } ImmutablePair(A first, B second); static ImmutablePair<A, B> of(A first, B second); A getFirst(); B getSecond(); @Override String toString(); @Override int hashCode(); @Override boolean equals(Object o);  }### Answer:
@Test public void testGetFirst() throws Exception { Assert.assertEquals(Integer.class, Fixture.a.getFirst().getClass()); Assert.assertEquals(1, Fixture.a.getFirst().intValue()); }