code: public void setContent(IContent content)
  	{
  		this.content = content;
  		content.setParent(this);
  		content.setPosition(Position.middleCenter(content));
  		contentSize = content.size().plus(Size.of(6, 6));
  	}
docs: Sets the content for this {@link UICheckBox}.
  
  @param content the content