public V remove(long key) {
        long h = hash(key);
        return getSection(h).remove(key, null, (int) h);
    }
@Test
    public void testRemove() {
        ConcurrentLongHashMap<String> map = ConcurrentLongHashMap.<String>newBuilder()
                .build();

        assertTrue(map.isEmpty());
        assertNull(map.put(1, "one"));
        assertFalse(map.isEmpty());

        assertFalse(map.remove(0, "zero"));
        assertFalse(map.remove(1, "uno"));

        assertFalse(map.isEmpty());
        assertTrue(map.remove(1, "one"));
        assertTrue(map.isEmpty());
    }