request_data (WWW::Mechanize::Form)

    # File lib/www/mechanize/form.rb, line 213
          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
              WWW::Mechanize::Util.build_query_string(query_params)
            end
          end