add_associations

# File activerecord/lib/active_record/serializers/xml_serializer.rb, line 198
    def add_associations(association, records, opts)
      association_name = association.to_s.singularize
      merged_options   = options.merge(opts).merge!(:root => association_name, :skip_instruct => true)

      if records.is_a?(Enumerable)
        tag  = ActiveSupport::XmlMini.rename_key(association.to_s, options)
        type = options[:skip_types] ? { } : {:type => "array"}

        if records.empty?
          @builder.tag!(tag, type)
        else
          @builder.tag!(tag, type) do
            records.each do |record|
              if options[:skip_types]
                record_type = {}
              else
                record_class = (record.class.to_s.underscore == association_name) ? nil : record.class.name
                record_type = {:type => record_class}
              end

              record.to_xml merged_options.merge(record_type)
            end
          end
        end
      elsif record = @serializable.send(association)
        record.to_xml(merged_options)
      end
    end