This event gets triggered when a new
DynamicRegistryManager gets created, but before it gets filled.
Therefore, this is the ideal place to register callbacks to dynamic registries.
For example, the following code is used to register a callback that gets triggered for any registered Biome, both JSON and code defined.
DynamicRegistrySetupCallback.EVENT.register(registryManager -> {
Registry<Biome> biomes = registryManager.get(Registry.BIOME_KEY);
RegistryEntryAddedCallback.event(biomes).register((rawId, id, object) -> {
// Do something
});
});