code: func (r *GormWorkItemTypeRepository) loadChildTypeList(ctx context.Context, parentTypeID uuid.UUID) ([]uuid.UUID, error) {
  	types := []ChildType{}
  	db := r.db.Model(&types).Where("parent_work_item_type_id=?", parentTypeID).Order("position ASC").Find(&types)
  	if db.RecordNotFound() {
  		log.Error(ctx, map[string]interface{}{"wit_id": parentTypeID}, "work item type child types not found")
  		return nil, errors.NewNotFoundError("work item type child types", parentTypeID.String())
  	}
  	if err := db.Error; err != nil {
  		return nil, errors.NewInternalError(ctx, err)
  	}
  	res := make([]uuid.UUID, len(types))
  	for i, childType := range types {
  		res[i] = childType.ChildWorkItemTypeID
  	}
  	return res, nil
  }
docs: // loadChildTypeList loads all child work item types associated with the given
  // work item type