# File lib/mechanize/util.rb, line 12
      def build_query_string(parameters, enc=nil)
        parameters.map { |k,v|
          # WEBrick::HTTP.escape* has some problems about m17n on ruby-1.9.*.
          [CGI.escape(k.to_s), CGI.escape(v.to_s)].join("=") if k
        }.compact.join('&')
      end