@Mod(AlchemicalBees.MODID)
public class AlchemicalBees {
    // Directly reference a log4j logger.

    public static final String MODID = "alchemicalbees";
    public static ItemGroup ITEM_GROUP;
    private static final Logger LOGGER = LogManager.getLogger();

    public static final IProxy PROXY = DistExecutor.safeRunForDist(() -> ClientProxy::new, () -> ServerProxy::new);

    private static final String[] LOCALES = new String[]{
            "en_us",
            "en_uk"
    };

    public AlchemicalBees() {
        IEventBus mod = FMLJavaModLoadingContext.get().getModEventBus();
        IEventBus forge = MinecraftForge.EVENT_BUS;

        PROXY.setup(mod, forge);
        addRegistries(mod);
        mod.addListener(this::commonSetup);
        mod.addListener(this::gatherData);
    }

    private void commonSetup(final FMLCommonSetupEvent event) {

    }

    private void addRegistries(IEventBus mod) {
        ALBItem.generateItems();
        ALBBlock.generateBlocks();
        ITEM_GROUP = new ItemGroup("alchemical_bees") {
            @Override
            @OnlyIn(Dist.CLIENT)
            public ItemStack createIcon() {
                return new ItemStack(ALBItem.registeredItems.get("royal_jelly").item.get());
            }
        };
        ALBItem.addToTab();
        ALBItem.ITEMS.register(mod);
        ALBBlock.BLOCKS.register(mod);
    }

    private void gatherData(final GatherDataEvent event) {
        LOGGER.debug("Running data gen #1");
        DataGenerator gen = event.getGenerator();
        if (event.includeClient()) {
            LOGGER.debug("Running data gen #2");
            ExistingFileHelper efh = event.getExistingFileHelper();

            gen.addProvider(new ALBItemModelProvider(gen, efh));
            gen.addProvider(new ALBBlockStateProvider(gen, efh));
            addLanguageProviders(gen);
            LOGGER.debug("Running data gen #6");
        }
    }

    private void addLanguageProviders(final DataGenerator gen) {
        for (String locale : LOCALES) {
            gen.addProvider(new ALBLanguageProvider(gen, locale));
        }
    }
}

public class ALBBlockStateProvider extends BlockStateProvider {

    private static final Logger LOGGER = LogManager.getLogger();

    public ALBBlockStateProvider(DataGenerator gen, ExistingFileHelper efh) {
        super(gen, AlchemicalBees.MODID, efh);
    }

    @Override
    public void registerStatesAndModels() {
        LOGGER.debug("Running data gen #5");
        ALBBlock.registeredBlocks.forEach((k, v) -> {
            if (v instanceof PipeBlock) {
                generatePipeTemplate(v);
            } else if (v.getModelPath() == null) {
                basicBlock(v);
            } else {
                modelBlock(v);
            }
        });
    }
...

public class ALBItemModelProvider extends ItemModelProvider {

    private static final Logger LOGGER = LogManager.getLogger();

    public ALBItemModelProvider(DataGenerator generator, ExistingFileHelper existingFileHelper) {
        super(generator, AlchemicalBees.MODID, existingFileHelper);
    }

    @Override
    protected void registerModels() {
        LOGGER.debug("Running data gen #3");
        ALBItem.registeredItems.forEach((k, v) -> {
            if (!v.isBlockItem){
                simpleItem(v.item);
            }
        });
    }

...

public class ALBLanguageProvider extends LanguageProvider {

    private static final Logger LOGGER = LogManager.getLogger();

    public ALBLanguageProvider(DataGenerator gen, String locale) {
        super(gen, AlchemicalBees.MODID, locale);
    }

    @Override
    protected void addTranslations() {
        LOGGER.debug("Running data gen #4");
        String locale = this.getName().replace("Languages: ", "");
        ALBItem.registeredItems.forEach((k, v) -> {
            String translation = v.translations.get(locale);
            if (translation != null) {
                addItem(v.item, translation);
            }
        });
        ALBBlock.registeredBlocks.forEach((k, v) -> {
            String translation = v.translations.get(locale);
            if (translation != null) {
                addBlock(v.block, translation);
            }
        });
    }
}


public abstract class ALBItem {

    public boolean isBlockItem = false;

    public static void generateItems() {
        registerItem("royal_jelly", new RoyalJelly());
    }

    public static void addToTab() {
        registeredItems.forEach((k, v) -> {
            v.properties.group(AlchemicalBees.ITEM_GROUP);
        });
    }

    public abstract void addTranslations(Map<String, String> translations);

    public abstract void addProperties(Item.Properties properties);

    public void setID(String id) {
        this.itemID = id;
    }

    public String itemID;
    public Map<String, String> translations = new HashMap<>();
    public RegistryObject<Item> item;
    public Item.Properties properties = new Item.Properties();

    public static final DeferredRegister<Item> ITEMS = DeferredRegister.create(ForgeRegistries.ITEMS, AlchemicalBees.MODID);
    public static Map<String, ALBItem> registeredItems = new HashMap<>();

    public static void registerItem(String id, ALBItem item) {
        // set item id
        item.setID(id);
        // add item properties
        item.addProperties(item.properties);
        // add translations
        item.addTranslations(item.translations);
        // register item
        item.item = ITEMS.register(id, () -> new Item(item.properties));

        registeredItems.put(id, item);
    }
}


// fails to run all data gen
[12:35:19] [main/DEBUG] [ne.mi.fm.ja.FMLModContainer/LOADING]: Firing event for modid alchemicalbees : net.minecraftforge.fml.event.lifecycle.GatherDataEvent@79f14c56
[12:35:19] [main/DEBUG] [co.da.al.co.AlchemicalBees/]: Running data gen #1
[12:35:19] [main/DEBUG] [co.da.al.co.AlchemicalBees/]: Running data gen #2
[12:35:19] [main/DEBUG] [co.da.al.co.AlchemicalBees/]: Running data gen #7
[12:35:19] [main/DEBUG] [ne.mi.fm.ja.FMLModContainer/LOADING]: Fired event for modid alchemicalbees : net.minecraftforge.fml.event.lifecycle.GatherDataEvent@79f14c56