code: public void sendToAllExceptUser(String topicURI, Object event, String excludeUser) {
  		sendToAllExceptUsers(topicURI, event, Collections.singleton(excludeUser));
  	}
docs: Send an {@link EventMessage} to every client that is currently subscribed to the
  provided topicURI except the one provided with the excludeUser parameter.
  
  @param topicURI the name of the topic
  @param event the payload of the {@link EventMessage}
  @param user the user that will be excluded