/*
 *  call-seq:
 *    namespace()
 *
 *  returns the namespace prefix for the node, if one exists.
 */
static VALUE namespace(VALUE self)
{
  xmlNodePtr node ;
  Data_Get_Struct(self, xmlNode, node);
  if (node->ns && node->ns->prefix) {
    return NOKOGIRI_STR_NEW2(node->ns->prefix, node->doc->encoding);
  }
  return Qnil ;
}