src/game/java/net/minecraft/server/RegistryLayer.java

package net.minecraft.server;

import java.util.List;
import net.minecraft.core.LayeredRegistryAccess;
import net.minecraft.core.RegistryAccess;
import net.minecraft.core.registries.BuiltInRegistries;

public enum RegistryLayer {
    STATIC,
    WORLDGEN,
    DIMENSIONS,
    RELOADABLE;

    private static final List<RegistryLayer> VALUES = List.of(values());
    private static final RegistryAccess.Frozen STATIC_ACCESS = RegistryAccess.fromRegistryOfRegistries(BuiltInRegistries.REGISTRY);

    public static LayeredRegistryAccess<RegistryLayer> createRegistryAccess() {
        return new LayeredRegistryAccess<>(VALUES).replaceFrom(STATIC, STATIC_ACCESS);
    }
}