code: public void drawGroup(Object parent, Object object, Style style) {
  		createOrUpdateGroup(parent, object, null, style);
  	}
docs: Creates a group element in the technology (SVG/VML/...) of this context. A group is meant to group other elements
  together, and in this case applying a style on them.
  
  @param parent
  parent group object
  @param object
  group object
  @param style
  Add a style to a group.