for (User user : addedUsers) {
fireChatUserAdded(chat, user);
}
break;
case LEFT:
LeaveReason leaveReason = chatMessage.getLeaveReason();
if (leaveReason.equals(LeaveReason.UNSUBSCRIBE)) {
User user = chatMessage.getSender();
fireChatUserLeft(chat, user);
}
break;
default: