gistfile1.txt

@EqualsAndHashCode(of = "handle")
@Getter
public class AbstractWrapper {

    private final Object handle;
    private final Class<?> handleClass;

    public AbstractWrapper(Object handle, Class<?> handleClass) {
        if (!handleClass.isInstance(handle)) throw new IllegalArgumentException(handle.getClass().getSimpleName()+ " cannot be handled from wrapper with "+handleClass.getSimpleName());
        this.handle = handle;
        this.handleClass = handleClass;
    }

    @Override
    public String toString() {
        return handle.toString();
    }

}

gistfile2.txt

public class WrappedNBTTagCompound extends AbstractWrapper {

    protected static final Class<?> typeClass = NMSReflection.getNMSClass("NBTTagCompound");

    private final HashMap<String, ?> map;

    public WrappedNBTTagCompound(Object handle) {
        super(handle, typeClass);
        map = (HashMap) NMSReflection.getField(handle, "map");
    }

    public boolean isList(String s) {
        return WrappedNBTTagList.typeClass.isInstance(map.get(s));
    }

    public boolean isCompound(String s) {
        return WrappedNBTTagCompound.typeClass.isInstance(map.get(s));
    }

    public WrappedNBTTagCompound getCompound(String s) {
        return new WrappedNBTTagCompound(map.get(s));
    }

    public WrappedNBTTagList getList(String s) {
        return new WrappedNBTTagList(map.get(s));
    }

    public void remove(String s) {
        map.remove(s);
    }

    public Set<String> getKeys() {
        return map.keySet();
    }

}

gistfile3.txt

public class WrappedNBTTagList extends AbstractWrapper implements Iterable {

    protected static final Class<?> typeClass = NMSReflection.getNMSClass("NBTTagList");

    private final List list;

    public WrappedNBTTagList(Object handle) {
        super(handle, typeClass);
        list = (List) NMSReflection.getField(handle, "list");
    }

    public boolean isList(int i) {
        return WrappedNBTTagList.typeClass.isInstance(list.get(i));
    }

    public boolean isCompound(int i) {
        return WrappedNBTTagCompound.typeClass.isInstance(list.get(i));
    }

    public WrappedNBTTagCompound getCompound(int i) {
        return new WrappedNBTTagCompound(list.get(i));
    }

    public WrappedNBTTagList getList(int i) {
        return new WrappedNBTTagList(list.get(i));
    }

    public void remove(int i) {
        list.remove(i);
    }

    public int size() {
        return list.size();
    }

    @Override
    public Iterator iterator() {
        return list.iterator();
    }

}