public static <K, V> ConcurrentMap<K, V> newConcurrentWeakHashMap(int expectedSize) {
        return new ConcurrentReferenceHashMap<>(computeMapInitialCapacity(expectedSize), ConcurrentReferenceHashMap.ReferenceType.WEAK);
    }
Instantiate a new {@code ConcurrentWeakHashMap} with an initial capacity
that can accommodate the specified number of elements without
any immediate resize/rehash operations to be expected.

@param expectedSize the expected number of elements (with a corresponding
                    capacity to be derived so that no resize/rehash operations are needed)
ttl-core/src/main/java/com/alibaba/ttl3/internal/util/Utils.java