public virtual void TestRemoveByObjectReference()
        {
            ObjectReference ref1 = NewObjectReference();

            _referenceSystem1.AddExistingReference(ref1);
            ObjectReference ref2 = NewObjectReference();

            _referenceSystem2.AddExistingReference(ref2);
            _registry.RemoveReference(ref2);
            Assert.IsNotNull(_referenceSystem1.ReferenceForId(TestId));
            Assert.IsNull(_referenceSystem2.ReferenceForId(TestId));
        }