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

  xmlNodePtr root = xmlDocGetRootElement(doc);

  if(!root) return Qnil;
  return Nokogiri_wrap_xml_node(root) ;
}