prefactor: extract Searchable#get_xpath_context

lib/nokogiri/xml/searchable.rb

@@ -261,14 +261,19 @@ def xpath_internal(node, paths, handler, ns, binds)
       end
 
       def xpath_impl(node, path, handler, ns, binds)
-        ctx = XPathContext.new(node)
+        ctx = get_xpath_context(node)
+
         ctx.register_namespaces(ns)
         ctx.register_variables(binds)
 
         path = path.gsub("xmlns:", " :") unless Nokogiri.uses_libxml?
 
         ctx.evaluate(path, handler)
       end
+
+      def get_xpath_context(node)
+        XPathContext.new(node)
+      end
     end
   end
 end