code: public int put(Iterable<? extends Widget> widgets) throws IndexOutOfBoundsException {
  		int last = -1;
  		for (Widget widget : widgets) {
  			last = put(widget);
  		}
  		return last;
  	}
docs: Adds all widgets from given iterable
  
  @param widgets Iterable object containing widgets
  @return Index of last added element
  @throws IndexOutOfBoundsException when there is no more space