code: public ModelBuilder subTypes(List<ModelReference> subTypes) {
      if (subTypes != null) {
        this.subTypes.addAll(subTypes);
      }
      return this;
    }
docs: Updates the subclasses for this model.
  
  @param subTypes - Models inheriting from this model
  @return this
  @since 2.8.1 We changed the subType to be a model refers