- distinct by one property
private static <T> Predicate<T> distinctByKey(Function<? super T, ?> keyExtractor) {
Map<Object,Boolean> seen = new ConcurrentHashMap<>();
return t -> seen.putIfAbsent(keyExtractor.apply(t), Boolean.TRUE) == null;
}
list.filter(distinctByKey(VMEnterpriseTag::getTag)).collect(Collectors.toList());