/// <exception cref="System.Exception"></exception>
		public virtual void SetUp()
		{
			_registry = new ReferenceSystemRegistry();
			_referenceSystem1 = new TransactionalReferenceSystem();
			_referenceSystem2 = new TransactionalReferenceSystem();
			_registry.AddReferenceSystem(_referenceSystem1);
			_registry.AddReferenceSystem(_referenceSystem2);
		}
		private void RemoveReference(ReferenceSystemRegistry.IReferenceSource referenceSource
			)
		{
			IEnumerator i = _referenceSystems.GetEnumerator();
			while (i.MoveNext())
			{
				IReferenceSystem referenceSystem = (IReferenceSystem)i.Current;
				ObjectReference reference = referenceSource.ReferenceFrom(referenceSystem);
				if (reference != null)
				{
					referenceSystem.RemoveReference(reference);
				}
			}
		}