for (DataCommand.ObjectType objectType : TARGET_OBJECT_TYPES)

public static void register(CommandDispatcher<ServerCommandSource> dispatcher) {
    LiteralArgumentBuilder<ServerCommandSource> literalArgumentBuilder = CommandManager.literal("data").requires(source -> source.hasPermissionLevel(2));

    for (DataCommand.ObjectType objectType : TARGET_OBJECT_TYPES) {
       literalArgumentBuilder.then(
             objectType.addArgumentsToBuilder(
                CommandManager.literal("merge"),
                builder -> builder.then(
                      CommandManager.argument("nbt", NbtCompoundArgumentType.nbtCompound())
                         .executes(context -> executeMerge(context.getSource(), objectType.getObject(context), NbtCompoundArgumentType.getNbtCompound(context, "nbt")))
                   )
             )
          )
.then(
             addModifyArgument(   //this section is not using  objectType                 (builder, modifier) -> builder.then(
                         CommandManager.literal("insert")
                            .then(
                               CommandManager.argument("index", IntegerArgumentType.integer())
                                  .then(modifier.create((context, sourceNbt, path, elements) -> path.insert(IntegerArgumentType.getInteger(context, "index"), sourceNbt, elements)))
                            )
                      )
                      .then(CommandManager.literal("prepend").then(modifier.create((context, sourceNbt, path, elements) -> path.insert(0, sourceNbt, elements))))
                      .then(CommandManager.literal("append").then(modifier.create((context, sourceNbt, path, elements) -> path.insert(-1, sourceNbt, elements))))
                      .then(CommandManager.literal("set").then(modifier.create((context, sourceNbt, path, elements) -> path.put(sourceNbt, Iterables.getLast(elements)))))
                      .then(CommandManager.literal("merge").then(modifier.create((context, element, path, elements) -> {
                         NbtCompound nbtCompound = new NbtCompound();

                         for (NbtElement nbtElement : elements) {
                            if (NbtPathArgumentType.NbtPath.isTooDeep(nbtElement, 0)) {
                               throw NbtPathArgumentType.TOO_DEEP_EXCEPTION.create();
                            }

                            if (!(nbtElement instanceof NbtCompound nbtCompound2)) {
                               throw MODIFY_EXPECTED_OBJECT_EXCEPTION.create(nbtElement);
                            }

                            nbtCompound.copyFrom(nbtCompound2);
                         }

                         Collection<NbtElement> collection = path.getOrInit(element, NbtCompound::new);
                         int i = 0;

                         for (NbtElement nbtElement2 : collection) {
                            if (!(nbtElement2 instanceof NbtCompound nbtCompound3)) {
                               throw MODIFY_EXPECTED_OBJECT_EXCEPTION.create(nbtElement2);
                            }

                            NbtCompound nbtCompound4 = nbtCompound3.copy();
                            nbtCompound3.copyFrom(nbtCompound);
                            i += nbtCompound4.equals(nbtCompound3) ? 0 : 1;
                         }

                         return i;
                      })))
             )
          );
    }

    dispatcher.register(literalArgumentBuilder);
} 



private static ArgumentBuilder<ServerCommandSource, ?> addModifyArgument(
    BiConsumer<ArgumentBuilder<ServerCommandSource, ?>, DataCommand.ModifyArgumentCreator> subArgumentAdder
) {
    LiteralArgumentBuilder<ServerCommandSource> literalArgumentBuilder = CommandManager.literal("modify");

    for (DataCommand.ObjectType objectType : TARGET_OBJECT_TYPES) {
       objectType.addArgumentsToBuilder(  //instead creates its own objectType