gist.php

private function bootSpotifySocialite()
{
    $socialite = $this->app->make('Laravel\Socialite\Contracts\Factory');
    $socialite->extend(
        'spotify',
        function ($app) use ($socialite) {
            $config = $app['config']['services.spotify'];
            return $socialite->buildProvider(SpotifyProvider::class, $config);
        }
    );
}