def save
      __robject.content_type = model.content_type
      __robject.data = __persist_attributes

      __check_unique_indices
      __update_indices
      __robject.store

      @id = __robject.key

      self
    end
def save
      __robject.content_type = model.content_type
      __robject.data = __persist_attributes

      __check_unique_indices
      __update_indices
      __robject.store

      @id = __robject.key

      self
    end
Persist the model attributes and update indices and unique
 indices.

 Example:

   class User
     include Ork::Document

     attribute :name
   end

   u = User.new(:name => "John").save
   # => #<User:6kS5VHNbaed9h7gFLnVg5lmO4U7 {:name=>"John"}>