def remove_category(*categories)
      categories.each do |category|
        direct_category_items.where(category_id: category).destroy_all
      end
      @categories = nil
    end
def remove_category(*categories)
      categories.each do |category|
        direct_category_items.where(category_id: category).destroy_all
      end
      @categories = nil
    end
Public: Removes a category, or categories, from the model

 Examples:

   categorizable_object.remove_category dummy_category
   categorizable_object.remove_categories dummy_category1, dummy_category2