public bool RenameParticipant(String oldParticipantID, String newParticipantID)
        {
            try
            {
                Participant partOld = ParticipantsMap[oldParticipantID];
                ParticipantsMap.Remove(oldParticipantID);

                partOld.Id = newParticipantID;
                ParticipantsMap.Add(newParticipantID, partOld);
            }
            catch (ArgumentException)
            {
                return(false);
            }
            return(true);
        }
 public void DeleteParticipant(String participantID)
 {
     ParticipantsMap.Remove(participantID);
 }