## attributes=

def attributes=(new_attributes)
1505:         return if new_attributes.nil?
1506:         attributes = new_attributes.dup
1507:         attributes.stringify_keys!
1508:
1509:         multi_parameter_attributes = []
1510:         remove_attributes_protected_from_mass_assignment(attributes).each do |k, v|
1511:           k.include?("(") ? multi_parameter_attributes << [ k, v ] : send(k + "=", v)
1512:         end
1513:
1514:         assign_multiparameter_attributes(multi_parameter_attributes)
1515:       end

## assign_multipleparameter_attributes

    def assign_multiparameter_attributes(pairs)
        execute_callstack_for_multiparameter_attributes(
          extract_callstack_for_multiparameter_attributes(pairs)
        )
      end

      # Includes an ugly hack for Time.local instead of Time.new because the latter is reserved by Time itself.
      def execute_callstack_for_multiparameter_attributes(callstack)
        errors = []
        callstack.each do |name, values|
          klass = (self.class.reflect_on_aggregation(name.to_sym) || column_for_attribute(name)).klass
          if values.empty?
            send(name + "=", nil)
          else
            begin
              send(name + "=", Time == klass ? klass.local(*values) : klass.new(*values))
            rescue => ex
              errors << AttributeAssignmentError.new("error on assignment #{values.inspect} to #{name}", ex, name)
            end
          end
        end
        unless errors.empty?
          raise MultiparameterAssignmentErrors.new(errors), "#{errors.size} error(s) on assignment of multiparameter attributes"
        end
      end

      def extract_callstack_for_multiparameter_attributes(pairs)
        attributes = { }

        for pair in pairs
          multiparameter_name, value = pair
          attribute_name = multiparameter_name.split("(").first
          attributes[attribute_name] = [] unless attributes.include?(attribute_name)

          unless value.empty?
            attributes[attribute_name] <<
              [ find_parameter_position(multiparameter_name), type_cast_attribute_value(multiparameter_name, value) ]
          end
        end

        attributes.each { |name, values| attributes[name] = values.sort_by{ |v| v.first }.collect { |v| v.last } }
      end

      def type_cast_attribute_value(multiparameter_name, value)
        multiparameter_name =~ /\([0-9]*([a-z])\)/ ? value.send("to_" + $1) : value
      end

      def find_parameter_position(multiparameter_name)
        multiparameter_name.scan(/\(([0-9]*).*\)/).first.first
      end