# File lib/libxml/document.rb, line 130
      def node_type_name
        case node_type
          when XML::Node::DOCUMENT_NODE
            'document_xml'
          when XML::Node::DOCB_DOCUMENT_NODE
            'document_docbook'
          when XML::Node::HTML_DOCUMENT_NODE
            'document_html'
          else
            raise(UnknownType, "Unknown node type: %n", node.node_type);
        end
      end