Model.add_group Model.add_group(name, parent=None, attr=None, **kwargs) Add a group to the model. Parameters: namestrThe name of the group. parentGroupNode, optionalThe parent (group) node for the group. attrdict, optionalAdditional attributes to add to the group. **kwargsdict, optionalAdditional keyword arguments, which will be added to the attributes dict. Returns: GroupNode