import type { IDBSubnetGroupRef } from '../rds.generated';
import type { ISubnetGroup } from '../subnet-group';
/**
 * Convert an IBackupVaultRef to IBackupVault, throwing an error if the instance
 * doesn't implement the full IBackupVault interface.
 */
export declare function toISubnetGroup(group: IDBSubnetGroupRef): ISubnetGroup;