class REXML::XPathParser

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