/*
 * call-seq:
 *  url
 *
 * Get the url name for this document.
 */
static VALUE url(VALUE self)
{
  xmlDocPtr doc;
  Data_Get_Struct(self, xmlDoc, doc);

  if(doc->URL)
    return NOKOGIRI_STR_NEW2(doc->URL, doc->encoding);

  return Qnil;
}