public Object removeObject(Object key) {
		Object value = null;
		Object ref = cache.remove(key);
		if (ref != null) {
			if (ref instanceof StrongReference) {
				value = ((StrongReference) ref).get();
			} else if (ref instanceof SoftReference) {
				value = ((SoftReference) ref).get();
			} else if (ref instanceof WeakReference) {
				value = ((WeakReference) ref).get();
			}
		}
		return value;
	}