/// <summary>
 /// Changes Participant and therefore the inner state of the Session
 /// All new Pages and Strokes will be written to this new Participant-Object
 /// </summary>
 public bool NewParticipant(String participantID)
 {
     try
     {
         Participant participant = new Participant(participantID);
         ParticipantsMap.Add(participantID, participant);
         CurrentParticipantID = participantID;
         CurrentPage          = null;
         return(true);
     }
     catch (Exception e) {
         return(false);
     }
 }
        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);
 }