where to find the static get post put delete patch of laravel 5.x.x Route class?

in the api.php we can state routes like this

Route::post('/test','TestController@test');
Route::get('/test2','TestController@test2');
Route::delete('/test3','TestController@test3');

but when I checked the Route Class Symfony\Component\Routing;

I don't see any static post, get , delete, patch,put functions... where can i find this ? and how these static calls gets detected ?

via Chebli Mohamed