// No filter and no select-clause: return underlying event public virtual Object Evaluate( EventBean[] eventsPerStream, bool newData, ICollection <EventBean> matchingEvents, ExprEvaluatorContext exprEvaluatorContext, ExprSubselectRowNode parent) { if (matchingEvents.Count > 1) { Log.Warn(parent.GetMultirowMessage()); return(null); } return(EventBeanUtility.GetNonemptyFirstEventUnderlying(matchingEvents)); }