Pair implements Serializable { public Pair(E1 first, E2 second) { mFirst = first; mSecond = second; } Pair(E1 first, E2 second); E1 first(); E2 second(); void setFirst(E1 first); void setSecond(E2 second); @Override boolean equals(Object obj); @Override int hashCode();  }
@Test public void testPair() { Pair<String, String> pair = new Pair<String, String>("a", "b"); assertNotNull(pair); }