Laravel 5.1: How AuthController runs methods not implemented in its file?

I've implemented the Basic Authentication described on the Laravel docs.

Part of the process is setting up Routes for Authentication on the routes.php file:

// Authentication routes...
Route::get('auth/login', 'Auth\AuthController@getLogin');
Route::post('auth/login', 'Auth\AuthController@postLogin');
Route::get('auth/logout', 'Auth\AuthController@getLogout');

// Registration routes...
Route::get('auth/register', 'Auth\AuthController@getRegister');
Route::post('auth/register', 'Auth\AuthController@postRegister');

But, going through the AuthController inside the Auth directory, I cannot find those methods (getLogin, postLogin, etc.).

How does this work if the methods aren't there?

or

Where are those methods?

via Chebli Mohamed