*
 * <pre>{@code
 * FluentFuture<UserName> userName =
 *     ClosingFuture.submit(
 *             closer -> closer.eventuallyClose(database.newTransaction(), closingExecutor),
 *             executor)
 *         .transformAsync((closer, transaction) -> transaction.queryClosingFuture("..."), executor)
 *         .transform((closer, result) -> result.get("userName"), directExecutor())

    /** The key of the message: Username */
    public static final String LABELS_user_name = "{labels.user_name}";

    /** The key of the message: Login */
    public static final String LABELS_LOGIN = "{labels.login}";

    /** The key of the message: Username */
    public static final String LABELS_LOGIN_placeholder_username = "{labels.login.placeholder_username}";

    /** The key of the message: Password */

    public static final String ERRORS_APP_DOUBLE_SUBMIT_REQUEST = "{errors.app.double.submit.request}";

    /** The key of the message: Username or Password is not correct. */
    public static final String ERRORS_login_error = "{errors.login_error}";

    /** The key of the message: Failed to process SSO login. */

 * credentials with this file or pipe. This can be used to retrieve the
 * username for example:
 * <tt>
 * String username = f.getPrincipal().getName();
 * </tt>
 * The <tt>Principal</tt> object returned will never be <tt>null</tt>
 * however the username can be <tt>null</tt> indication anonymous
 * credentials were used (e.g. some IPC$ services).
 */