public static <E> Set<E> createHashSet(int expectedMapSize) {
        final int initialCapacity = (int) (expectedMapSize / HASHSET_DEFAULT_LOAD_FACTOR) + 1;
        return new HashSet<>(initialCapacity, HASHSET_DEFAULT_LOAD_FACTOR);
    }
@Test
    public void testCreateHashSet() {
        Set set = createHashSet(5);
        assertInstanceOf(HashSet.class, set);
    }