code: public synchronized EventScope<T> register(final Class<? extends T> eventClass, final Object receiver,
  			final Method handler) {
  
  		this.registerInternal(receiver, handler, eventClass);
  		return this;
  
  	}
docs: The public method to register a new event receiver.
  
  @param eventClass
  the class of event to be received.
  @param receiver
  The receiver to get the event.
  @param handler
  handler method to handle specified event.
  @return this to enable chaining.