code: @AnyThread
      public void bodyRemovedFromChannel (ChatChannel channel, final int bodyId)
      {
          _peerMan.invokeNodeAction(new ChannelAction(channel) {
              @Override protected void execute () {
                  ChannelInfo info = _channelMan._channels.get(_channel);
                  if (info != null) {
                      info.participants.remove(bodyId);
                  } else if (_channelMan._resolving.containsKey(_channel)) {
                      log.warning("Oh for fuck's sake, distributed systems are complicated",
                                  "channel", _channel);
                  }
              }
          });
      }
docs: When a body loses channel membership, this method should be called so that any server that
  happens to be hosting that channel can be told that the body in question is now a
  participant.