private WeakRefTracker _tracker;        // storage for weak proxy's

            private void Initialize(Struct s) {
                _formatString = s._formatString;
                _formats = s._formats;
                _isStandardized = s._isStandardized;
                _isLittleEndian = s._isLittleEndian;
                _encodingCount = s._encodingCount;
                _encodingSize = s._encodingSize;
                _tracker = s._tracker;
            }

 void IWeakReferenceable.SetFinalizer(WeakRefTracker value) {
     _tracker = value;
 }

 bool IWeakReferenceable.SetWeakRef(WeakRefTracker value) {
     _weakRefTracker = value;
     return true;
 }

 void IWeakReferenceable.SetFinalizer(WeakRefTracker value) {
     UserTypeOps.SetFinalizerHelper(this, value);
 }

 void IWeakReferenceable.SetFinalizer(WeakRefTracker value) {
     ((IWeakReferenceable)this).SetWeakRef(value);
 }

 public bool SetWeakRef(WeakRefTracker value)
 {
     tracker = value;
     return true;
 }

 public void SetFinalizer(WeakRefTracker value)
 {
     tracker = value;
 }

 bool IWeakReferenceable.SetWeakRef(WeakRefTracker value) {
     EnsureDict();
     _dict["__weakref__"] = value;
     return true;
 }

 bool IWeakReferenceable.SetWeakRef(WeakRefTracker value) {
     EnsureDict();
     _dict[Symbols.WeakRef] = value;
     return true;
 }

 public void SetFinalizer(WeakRefTracker value)
 {
     SetWeakRef(value);
 }

 public bool SetWeakRef(WeakRefTracker value) {
     return Interlocked.CompareExchange(ref _tracker, value, null) == null;
 }

 void IWeakReferenceable.SetFinalizer(WeakRefTracker obj0) {
     UserTypeOps.SetFinalizerHelper((IPythonObject)this, obj0);
 }