code: public void clientSessionDidStart (PresentsSession client)
      {
          if (ignoreClient(client)) {
              return;
          }
  
          // create and publish a ClientInfo record for this client
          ClientInfo clinfo = createClientInfo();
          initClientInfo(client, clinfo);
  
          // sanity check
          if (_nodeobj.clients.contains(clinfo)) {
              log.warning("Received clientSessionDidStart() for already registered client!?",
                          "old", _nodeobj.clients.get(clinfo.getKey()), "new", clinfo);
              // go ahead and update the record
              _nodeobj.updateClients(clinfo);
          } else {
              _nodeobj.addToClients(clinfo);
          }
      }
docs: from interface ClientManager.ClientObserver