### Question:
TinySet extends AbstractProxySet<E> { public static <T> Set<T> remove(Set<T> set, Object o) { if (set.isEmpty()) { return set; } else if (set.size() == 1) { if (set.contains(o)) { return Collections.emptySet(); } return set; } else { if (set.remove(o)) { return resetStorage(set); } return set; } }  static Set<T> add(Set<T> input, T e); static Set<T> addAll(Set<T> input, Collection<? extends T> c); static Set<T> remove(Set<T> set, Object o); static Set<T> removeAll(Set<T> set, Collection<T> c); static Set<T> retainAll(Set<T> mySet, Collection<?> c); @Override boolean add(E e); @Override boolean addAll(Collection<? extends E> c); @Override void clear(); @Override boolean remove(Object o); @Override boolean removeAll(Collection<?> c); @Override boolean retainAll(Collection<?> c);  }### Answer:
@Test public void testRemove() { TinySet<Object> set = new TinySet<>(); Assert.assertFalse(set.remove(TEST_OBJ2)); checkSize0(set); Assert.assertTrue(set.add(TEST_OBJ1)); checkSize1(set); Assert.assertFalse(set.remove(TEST_OBJ2)); checkSize1(set); Assert.assertTrue(set.remove(TEST_OBJ1)); checkSize0(set); Assert.assertFalse(set.remove(TEST_OBJ1)); checkSize0(set); Assert.assertTrue(set.addAll(Arrays.asList(TEST_OBJ1, TEST_OBJ2, TEST_OBJ3))); checkSizeN(set, 3); Assert.assertTrue(set.remove(TEST_OBJ1)); checkSizeN(set, 2); Assert.assertFalse(set.remove(TEST_OBJ1)); checkSizeN(set, 2); Assert.assertTrue(set.remove(TEST_OBJ3)); checkSize1(set); Assert.assertTrue(set.remove(TEST_OBJ2)); checkSize0(set); }