# File lib/mechanize/form.rb, line 220
    def request_data
      query_params = build_query()
      case @enctype.downcase
      when /^multipart\/form-data/
        boundary = rand_string(20)
        @enctype = "multipart/form-data; boundary=#{boundary}"
        params = []
        query_params.each { |k,v| params << param_to_multipart(k, v) unless k.nil? }
        @file_uploads.each { |f| params << file_to_multipart(f) }
        params.collect { |p| "--#{boundary}\r\n#{p}" }.join('') +
          "--#{boundary}--\r\n"
      else
        Mechanize::Util.build_query_string(query_params)
      end
    end