extract_callstack_for_multiparameter_attributes

# File activerecord/lib/active_record/base.rb, line 3121
      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)

          parameter_value = value.empty? ? nil : type_cast_attribute_value(multiparameter_name, value)
          attributes[attribute_name] << [ find_parameter_position(multiparameter_name), parameter_value ]
        end

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