if (elementName.equals("group")) {
Model model = (Model) listOf.getParentSBMLObject();
GroupsModelPlugin extendeModel = (GroupsModelPlugin) model.getExtension(GroupsConstants.namespaceURI);
Group group = new Group();
extendeModel.addGroup(group);
return group;
} else if (elementName.equals("member")) {
Member member = new Member();
listOf.add(member);