When I use the Validation feature in Laravel, how can I add a pre-defined strings that are allowed in an Input?
例如，假设我希望输入只包含以下内容之一:foo,bar,baz，我该怎么做？
$validator = Validator::make($credentials, [
'profile' => 'required|max:255', // Here I want Predefined allowed values for it
]);