Dingo\Api\Provider\HttpServiceProvider::registerHttpValidation PHP Method

    protected function registerHttpValidation()
    {
        $this->app->singleton('api.http.validator', function ($app) {
            return new RequestValidator($app);
        });
        $this->app->singleton(Domain::class, function ($app) {
            return new Validation\Domain($this->config('domain'));
        });
        $this->app->singleton(Prefix::class, function ($app) {
            return new Validation\Prefix($this->config('prefix'));
        });
        $this->app->singleton(Accept::class, function ($app) {
            return new Validation\Accept($this->app[AcceptParser::class], $this->config('strict'));
        });
    }