Barryvdh\DomPDF\ServiceProvider::register PHP Method

    public function register()
    {
        $configPath = __DIR__ . '/../config/dompdf.php';
        $this->mergeConfigFrom($configPath, 'dompdf');
        $this->app->bind('dompdf.options', function () {
            $defines = $this->app['config']->get('dompdf.defines');
            if ($defines) {
                $options = [];
                foreach ($defines as $key => $value) {
                    $key = strtolower(str_replace('DOMPDF_', '', $key));
                    $options[$key] = $value;
                }
            } else {
                $options = $this->app['config']->get('dompdf.options');
            }
            return $options;
        });
        $this->app->bind('dompdf', function () {
            $options = $this->app->make('dompdf.options');
            $dompdf = new Dompdf($options);
            $dompdf->setBasePath(realpath(base_path('public')));
            return $dompdf;
        });
        $this->app->alias('dompdf', Dompdf::class);
        $this->app->bind('dompdf.wrapper', function ($app) {
            return new PDF($app['dompdf'], $app['config'], $app['files'], $app['view']);
        });
    }