apollo-core/src/main/java/com/ctrip/framework/apollo/core/utils/ApolloThreadFactory.java/ApolloThreadFactory/classify
class ApolloThreadFactory:  private static <T> void classify(Set<T> src, Set<T> des, ClassifyStandard<T> standard) {
    Set<T> set = new HashSet<>();
    for (T t : src) {
      if (standard.satisfy(t)) {
        set.add(t);
      }
    }
    src.removeAll(set);
    des.addAll(set);
  }