WeakReference
class WeakReference<T : Any>
Class WeakReference encapsulates weak reference to an object, which could be used to either retrieve a strong reference to an object, or return null, if object was already destoyed by the memory manager.
Constructors
<init>
Creates a weak reference object pointing to an object. Weak reference doesn't prevent removing object, and is nullified once object is collected.
WeakReference(referred: T)