public BufferCollection getBufferList(Observer obs) {
    if (bufferCollection == null) return null;

    bufferCollection.addObserver(obs);
    return bufferCollection;
  }
 public void setMarkerLine(int bufferId, int msgId) {
   coreConn.requestSetMarkerLine(bufferId, msgId);
   bufferCollection.getBuffer(bufferId).setMarkerLineMessage(msgId);
 }
 public Buffer getBuffer(int bufferId, Observer obs) {
   bufferCollection.getBuffer(bufferId).addObserver(obs);
   // coreConn.requestBacklog(bufferId);
   return bufferCollection.getBuffer(bufferId);
 }
 public void setLastSeen(int bufferId, int msgId) {
   coreConn.requestSetLastMsgRead(bufferId, msgId);
   bufferCollection.getBuffer(bufferId).setLastSeenMessage(msgId);
 }