add getParent function

aixml/include/aixml/node.h

@@ -349,6 +349,7 @@ class AIXMLDLLEXPORT node {
   std::string name;
 
   auto getChildren() const -> const std::vector<node*>& { return children; }
+  auto getParent() const -> const node* { return parent; }
 
  private:
   std::map<std::string, std::string> attributes;