code: public void addElement(Element element) throws BadElementException {
  		if (cellgroup) {
  			if (element instanceof SimpleCell) {
  				if(((SimpleCell)element).isCellgroup()) {
  					throw new BadElementException("You can't add one row to another row.");
  				}
  				content.add(element);
  				return;
  			}
  			else {
  				throw new BadElementException("You can only add cells to rows, no objects of type " + element.getClass().getName());
  			}
  		}
  		if (element.type() == Element.PARAGRAPH
  				|| element.type() == Element.PHRASE
  				|| element.type() == Element.ANCHOR
  				|| element.type() == Element.CHUNK
  				|| element.type() == Element.LIST
  				|| element.type() == Element.MARKED
  				|| element.type() == Element.JPEG
  				|| element.type() == Element.JPEG2000
  				|| element.type() == Element.JBIG2
  				|| element.type() == Element.IMGRAW
  				|| element.type() == Element.IMGTEMPLATE) {
  			content.add(element);
  		}
  		else {
  			throw new BadElementException("You can't add an element of type " + element.getClass().getName() + " to a SimpleCell.");
  		}
  	}
docs: Adds content to this object.
  @param element
  @throws BadElementException