Proxy interfaces allow to mimic guest language objects in Graal languages. For example, one can
implement the ProxyObject interface and then pass the object
to a guest language. The guest language will then treat this instance as an object. Multiple
proxy interfaces can be implemented at the same time. So in a configuration a value can be an
array and an object at the same time.
If an object directly and exclusively implements the Proxy interface then the object can
be passed around in guest language. However, most operations with the value in guest language