public static <T> Set<T> newHashSetOnNull(Set<T> set) {
        if (set == null) {
            set = new HashSet<T>();
        }
        return set;
    }
@author Robert HG (254963746@qq.com) on 6/23/14.
lts-core/src/main/java/com/github/ltsopensource/core/commons/utils/CollectionUtils.java