In what file does the binding of request key to the service container of Request Facade happen in laravel?

Question

In the laravel Request facade we have the key 'request' being returned. To my understanding this is the key that is bound to the service container to resolve a class. In which file do we have the binding logic of the key happening?

<?php

namespace Illuminate\Support\Facades;
/*
 * @see \Illuminate\Http\Request
 */
class Request extends Facade
{
    /**
     * Get the registered name of the component.
     *
     * @return string
     */
    protected static function getFacadeAccessor()
    {
        return 'request';
    }
}