*             executor)
 *         .transformAsync((closer, transaction) -> transaction.queryClosingFuture("..."), executor)
 *         .transform((closer, result) -> result.get("userName"), directExecutor())
 *         .catching(DBException.class, e -> "no user", directExecutor())
 *         .finishToFuture();
 * }
 *
 * In this example, when the {@code userName} {@link Future} is done, the transaction and the query

 *             executor)
 *         .transformAsync((closer, transaction) -> transaction.queryClosingFuture("..."), executor)
 *         .transform((closer, result) -> result.get("userName"), directExecutor())
 *         .catching(DBException.class, e -> "no user", directExecutor())
 *         .finishToFuture();
 * }
 *
 * In this example, when the {@code userName} {@link Future} is done, the transaction and the query