Lists with compile time check over length

Main.java

import java.util.Arrays;
import java.util.List;
public class Main {

    static abstract class Num{
        public abstract int n();
        static class N0 extends N1{
            @Override
            public int n() {
                return 0;
            }
        }
        static class N1 extends N2 {
            @Override
            public int n() {
                return 1;
            }

        }
        static class N2 extends N3{
            @Override
            public int n() {
                return 2;
            }

        }
        static class N3 extends Num{
            @Override
            public int n() {
                return 3;
            }
        }

        private static final N0 N0 = new N0();
        private static final N1 N1 = new N1();
        private static final N2 N2 = new N2();
        private static final N3 N3 = new N3();

    }



    static class NList<N extends Num, E>{
        private final List<E> elementList;

        public <NN extends N> E get(NN n){
            return elementList.get(n.n());
        }


        public NList(E... es) {
            this.elementList = Arrays.asList(es);
        }


        public static <EE> NList<Num.N0, EE> of(EE e0){
            return new NList<Num.N0, EE>(e0);
        }

        public static <EE> NList<Num.N1, EE> of(EE e0, EE e1){
            return new NList<Num.N1, EE>(e0, e1);
        }

        public static <EE> NList<Num.N2, EE> of(EE e0, EE e1, EE e2){
            return new NList<Num.N2, EE>(e0, e1, e2);
        }

        public static <EE> NList<Num.N3, EE> of(EE e0, EE e1, EE e2, EE e3){
            return new NList<Num.N3, EE>(e0, e1, e2, e3);
        }

    }

    public static void main(String... args){
        NList<Num.N1, String> l1 = NList.of("a", "b");

        l1.get(Num.N0);
        l1.get(Num.N1);
        //l1.get(Num.N2); // does not compile

    }



}