### Question:
Pair { public A getFirst() { return first; } Pair(A f, B s); @Override int hashCode(); @Override boolean equals(Object o); A getFirst(); B getSecond(); @Override String toString(); String toString(String prefix, String separator, String suffix); Entry<A,B> toMapEntry(); Pair<B,A> swap(); static Pair<K2,V2> fromEntry(Entry<K1,V1> entry);  }### Answer:
@Test public void testGetFirst() { Pair<Integer,String> pair = new Pair<>(25, "twenty-five"); assertEquals((Integer) 25, pair.getFirst()); }