# File lib/em-http/http_encoding.rb, line 6
    def escape(s)
      if defined?(EscapeUtils)
        EscapeUtils.escape_url(s.to_s)
      else
        s.to_s.gsub(/([^a-zA-Z0-9_.-]+)/) {
          '%'+$1.unpack('H2'*bytesize($1)).join('%').upcase
        }
      end
    end