public IUndoableEdit ChangeState(State newState)
        {
            CompoundEdit ce = new CompoundEdit();

            if ((stateObject == null))
            {
                return(ce);
            }
            //check if the new state can apply to the statebean

            if (stateObject.GetParentObjectStates() != null)
            {
                foreach (IStateObject parentStateObject in stateObject.GetParentObjectStates())
                {
                    if (CompareState(parentStateObject.CurrentState, newState) < 0)
                    {
                        throw new Exception("The state cannot change, contains a greater state as a parent");
                    }
                }
            }
            if (stateObject.GetChildrenObjectStates() == null)
            {
                return(ce);
            }
            foreach (IStateObject o in stateObject.GetChildrenObjectStates())
            {
                if (o is Combination && stateObject is EquivalenceClass && newState != State.POSITIVE)
                {
                    ce.AddEdit(PropagateStateChangeInCombination((Combination)o, (EquivalenceClass)stateObject));
                }
                else
                {
                    StateObjectManager rlc = new StateObjectManager(o);
                    ce.AddEdit(rlc.ChangeState(newState));
                }
            }
            ce.AddEdit(EditFactory.instance.CreateChangeStateEdit(stateObject, newState));
            stateObject.CurrentState = newState;

            return(ce);
        }