descendant_recursive

# File lib/rexml/xpath_parser.rb, line 677
    def descendant_recursive(raw_node, new_nodeset, new_nodes, include_self)
      if include_self
        return if new_nodes.key?(raw_node)
        new_nodeset << XPathNode.new(raw_node, position: new_nodeset.size + 1)
        new_nodes[raw_node] = true
      end

      node_type = raw_node.node_type
      if node_type == :element or node_type == :document
        raw_node.children.each do |child|
          descendant_recursive(child, new_nodeset, new_nodes, true)
        end
      end
    end