class Nokogiri::XML::NodeSet

def xpath(*args)

For more information see Nokogiri::XML::Searchable#xpath

queries.
Search this node set for XPath +paths+. +paths+ must be one or more XPath

call-seq: xpath *paths, [namespace-bindings, variable-bindings, custom-handler-class]
## 
def xpath(*args)
  paths, handler, ns, binds = extract_params(args)
  inject(NodeSet.new(document)) do |set, node|
    set + xpath_internal(node, paths, handler, ns, binds)
  end
end