Transfer a MessagePort to a different vm Context. The original port object is rendered unusable, and the returned MessagePort instance takes its place.
The returned MessagePort is an object in the target context and inherits from its global Object class. Objects passed to the port.onmessage() listener are also created in the target context and inherit from its global Object class.
However, the created MessagePort no longer inherits from EventTarget, and only port.onmessage() can be used to receive events using it.