# File lib/xml/dom/core.rb, line 1310
      def push(*nodes)
        nodes.each do |node|
          if node.is_a?(Array)
            self.push(*node)
          elsif node.is_a?(NodeList)
            @nodes.concat(node.to_a)
          elsif node.is_a?(Node)
            @nodes << node
          else
            raise "parameter error"
          end
        end
        self
      end