* get the participants belonging to this shared context
* @return an arry of Participant instances, or null if there are no participants
*/
public IParticipant[] getParticipants(){
IPersistenceManager persistenceManager = PersistenceManagerFactory.getPersistenceManager();
return persistenceManager.findByValue(IParticipant.class, "sharedDataKey", this.sharedDataKey);
}
/**
* Add a participant to a shared context
* @param participantId the id property of the participant to add