Civi::$statics[__CLASS__]['links'][] = new CRM_Core_Reference_Basic(self::getTableName(), 'limit_listings_group_id', 'civicrm_group', 'id');
Civi::$statics[__CLASS__]['links'][] = new CRM_Core_Reference_Basic(self::getTableName(), 'add_to_group_id', 'civicrm_group', 'id');
Civi::$statics[__CLASS__]['links'][] = new CRM_Core_Reference_Basic(self::getTableName(), 'created_id', 'civicrm_contact', 'id');
Civi::$statics[__CLASS__]['links'][] = new CRM_Core_Reference_Basic(self::getTableName(), 'limit_listings_group_id', 'civicrm_group', 'id');
Civi::$statics[__CLASS__]['links'][] = new CRM_Core_Reference_Basic(self::getTableName(), 'add_to_group_id', 'civicrm_group', 'id');
Civi::$statics[__CLASS__]['links'][] = new CRM_Core_Reference_Basic(self::getTableName(), 'created_id', 'civicrm_contact', 'id');