Mã:
//class Test <X extends Number, Y, Z extends Double> {
class Test {

    static <T extends List, U> T removeObject(T list, U u) {

        Iterator<Iterator> it = list.iterator();
        while (it.hasNext()) {
            if (it.next() == u) {
                it.remove();
            }
        }

        return list;
    }

}




public class Solution {

    public static Scanner scanner = new Scanner(System.in);

    public static void main(String[] args) throws Exception {

        ArrayList list = new ArrayList<>();

        list.add("Hard");
        list.add(null);
        list.add(2344);
        list.add(0.35f);
        list.add(null);
        list.add('a');
        list.add(0.89d);
        list.add(null);
        list.add(13L);
        list.add(true);

        System.out.println("Input:");
        System.out.println(list);

        Test.removeObject(list, null);

        System.out.println("\nOutput:");
        System.out.println(list);

    }
}

Input:
[Hard, null, 2344, 0.35, null, a, 0.89, null, 13, true]

Output:
[Hard, 2344, 0.35, a, 0.89, 13, true]