void ISupportWorkflowChanges.OnActivityRemoved(ActivityExecutionContext executionContext, Activity removedActivity)
        {
            if (executionContext == null)
            {
                throw new ArgumentNullException("executionContext");
            }
            if (removedActivity == null)
            {
                throw new ArgumentNullException("removedActivity");
            }
            CompositeActivity activity = executionContext.Activity as CompositeActivity;

            if (activity == null)
            {
                throw new ArgumentException("Error_InvalidActivityExecutionContext", "executionContext");
            }
            activity.OnActivityChangeRemove(executionContext, removedActivity);
        }