    # File lib/active_record/base.rb, line 2733
          def attributes=(new_attributes, guard_protected_attributes = true)
            return if new_attributes.nil?
            attributes = new_attributes.dup
            attributes.stringify_keys!

            multi_parameter_attributes = []
            attributes = remove_attributes_protected_from_mass_assignment(attributes) if guard_protected_attributes

            attributes.each do |k, v|
              if k.include?("(")
                multi_parameter_attributes << [ k, v ]
              else
                respond_to?("#{k}=""#{k}=") ? send("#{k}=""#{k}=", v) : raise(UnknownAttributeError, "unknown attribute: #{k}")
              end
            end

            assign_multiparameter_attributes(multi_parameter_attributes)
          end