public class Solution {
    public static HashSet<Integer> createSet() {
        //напишите тут ваш код
        HashSet<Integer> set = new HashSet<Integer>();
        for (int i = 0; i < 20; i++) {
            set.add(i);
        }

        return set;
    }

    public static HashSet<Integer> removeAllNumbersMoreThan10(HashSet<Integer> set) {
        Collection<Integer> removeCandidates = new LinkedList<>();

        for (Integer element : set) {
            if (element > 10) {
                removeCandidates.add(element);
              set.removeAll(removeCandidates);
            }
        }
        return set;