modifiedDate = pd.getModifiedDate().getTime();
setInitiateByFirstWorkitem(pd.isInitiateByFirstWorkitem());
if(ptc!=null && isInitiateByFirstWorkitem()){
ActivityReference initiatorActRef = pd.getInitiatorHumanActivityReference(ptc);
HumanActivity initiatorHumanActivity = null;
if(initiatorActRef!=null)
initiatorHumanActivity = (HumanActivity)initiatorActRef.getActivity();
if(initiatorHumanActivity!=null)
//throw new RuntimeException(new UEngineException("Although this definition is set to be initiated by the first workitem, there's no initiating human activity."));
setInitiatorHumanActivityTracingTag(initiatorHumanActivity.getTracingTag());
}