if (!isset(Civi::$statics[__CLASS__]['links'])) {
Civi::$statics[__CLASS__]['links'] = static ::createReferenceColumns(__CLASS__);
Civi::$statics[__CLASS__]['links'][] = new CRM_Core_Reference_Basic(self::getTableName(), 'custom_group_id', 'civicrm_custom_group', 'id');
if (!isset(Civi::$statics[__CLASS__]['links'])) {
Civi::$statics[__CLASS__]['links'] = static ::createReferenceColumns(__CLASS__);
Civi::$statics[__CLASS__]['links'][] = new CRM_Core_Reference_Basic(self::getTableName(), 'custom_group_id', 'civicrm_custom_group', 'id');