collect_responses_and_parts_order

# File actionmailer/lib/action_mailer/base.rb, line 692
    def collect_responses_and_parts_order(headers) #:nodoc:
      responses, parts_order = [], nil

      if block_given?
        collector = ActionMailer::Collector.new(lookup_context) { render(action_name) }
        yield(collector)
        parts_order = collector.responses.map { |r| r[:content_type] }
        responses  = collector.responses
      elsif headers[:body]
        responses << {
          :body => headers.delete(:body),
          :content_type => self.class.default[:content_type] || "text/plain"
        }
      else
        templates_path = headers.delete(:template_path) || self.class.mailer_name
        templates_name = headers.delete(:template_name) || action_name

        each_template(templates_path, templates_name) do |template|
          self.formats = template.formats

          responses << {
            :body => render(:template => template),
            :content_type => template.mime_type.to_s
          }
        end
      end

      [responses, parts_order]
    end