### Question:
IsEquivalent implements BinaryPredicate<T, T> { @SuppressWarnings("unchecked") public static <T extends Comparable<?>> IsEquivalent<T> instance() { return new IsEquivalent<T>((Comparator<? super T>) ComparableComparator.INSTANCE); } @SuppressWarnings("unchecked")  IsEquivalent();  IsEquivalent(Comparator<? super T> comparator); boolean test(T left, T right); @Override boolean equals(Object obj); @Override int hashCode(); @Override String toString(); @SuppressWarnings("unchecked") static IsEquivalent<T> instance(); static Predicate<T> instance(T right); static final IsEquivalent<Comparable<?>> INSTANCE; }### Answer:
@Test public void testInstance() { assertTrue(IsEquivalent.instance("Xyzzy").test("Xyzzy")); assertTrue(!IsEquivalent.instance("Xyzzy").test("z")); }