docs: public static void propagateTypeError(
        Registry registry, Id id, Class<?> desiredClass, Class<?> actualClass) {
      final String dType = desiredClass.getName();
      final String aType = actualClass.getName();
      final String msg = String.format("cannot access '%s' as a %s, it already exists as a %s",
          id, dType, aType);
      registry.propagate(new IllegalStateException(msg));
    }