Have you had experience working with a non-standard WeakReference class (or similar)?

In Java, the WeakReference class is used to create weak references to objects, which do not prevent garbage collection. This is useful when you want to cache objects but do not want to keep them in memory if they are no longer in use.

Example usage:

import java.lang.ref.WeakReference;

public class WeakReferenceExample {
    public static void main(String[] args) {
        Object strongRef = new Object();
        WeakReference<Object> weakRef = new WeakReference<>(strongRef);

        System.out.println("Before nulling strongRef: " + weakRef.get());

        strongRef = null; // now the object is only accessible through the weak reference
        System.gc(); // invoke garbage collector

        System.out.println("After GC: " + weakRef.get()); // may be null if the object has been collected
    }
}

This approach helps manage memory, for example, in cache implementations where objects should be removed when memory is low but remain accessible if they are still alive. Weak references are also available in other languages and environments, such as WeakMap in JavaScript.