api/contact_group.go
func (a *API) DeleteContactGroup(cfg *ContactGroup) (bool, error) {
	if cfg == nil {
		return false, fmt.Errorf("Invalid contact group config [nil]")
	}
	return a.DeleteContactGroupByCID(CIDType(&cfg.CID))
}
func (a *API) DeleteContactGroup(cfg *ContactGroup) (bool, error) {
	if cfg == nil {
		return false, fmt.Errorf("Invalid contact group config [nil]")
	}
	return a.DeleteContactGroupByCID(CIDType(&cfg.CID))
}
// DeleteContactGroup deletes passed contact group.