def build_url                 
      parts = []
      uri   = ""
      parts << "/#{@version}"         if @version
      parts << "/#{@domain}"          if @domain
      parts << "/#{@service}"         if @service
      uri   =  parts.join("")
      parts << "?"
      parts << "format=#{@format}"
      parts << "&#{authentication_params(uri)}"
      parts << "#{format_parameters}" if @parameters
      @url = parts.join("")
    end
def build_url                 
      parts = []
      uri   = ""
      parts << "/#{@version}"         if @version
      parts << "/#{@domain}"          if @domain
      parts << "/#{@service}"         if @service
      uri   =  parts.join("")
      parts << "?"
      parts << "format=#{@format}"
      parts << "&#{authentication_params(uri)}"
      parts << "#{format_parameters}" if @parameters
      @url = parts.join("")
    end
build service url