====== Wrapper ======

Both primitive and objects that implements [[https://docs.oracle.com/javase/8/docs/api/java/io/Serializable.html|Serializable]] can be added in the graph, despite not being Node. Instead, a Wrapper Node is created to wrap the value of the primitive/Object. The wrapper is a Node, thus can be added in the graph. The wrapping and unwrapping is automatic.