code: public Element createOrUpdateGroup(Object parent, Object object, Matrix transformation, Style style) {
  		switch (namespace) {
  			case SVG:
  				return createSvgGroup(parent, object, transformation, style);
  			case VML:
  				return createVmlGroup(parent, object, transformation);
  			case HTML:
  			default:
  				return createHtmlGroup(parent, object, transformation, style);
  		}
  	}
docs: Creates a group element in the technology (SVG/VML/...) of this context. A group is meant to group other elements
  together. Also this method gives you the opportunity to specify a specific width and height.
  
  @param parent
  parent group object
  @param object
  group object
  @param transformation
  On each group, it is possible to apply a matrix transformation (currently translation only). This is
  the real strength of a group element. Never apply transformations on any other kind of element.
  @param style
  Add a style to a group.
  @return the group element