/**
* Implements hook_user_format_name_alter().
*/
-function {{ machine_name }}_user_format_name_alter(&$name, $account) {
+function {{ machine_name }}_user_format_name_alter(&$name, AccountInterface $account) {
// Display the user's uid instead of name.
if ($account->id()) {
$name = t('User @uid', ['@uid' => $account->id()]);