src/ContentNegotiationServiceProvider.php
public function boot(Application $app)
    {
        $app->before(array($this, "setRequestFormat"), Application::EARLY_EVENT);
        $app->before(array($this, "validateRequestContentType"), Application::EARLY_EVENT);
    }
public function boot(Application $app)
    {
        $app->before(array($this, "setRequestFormat"), Application::EARLY_EVENT);
        $app->before(array($this, "validateRequestContentType"), Application::EARLY_EVENT);
    }
Add filters to check that the request and repsonse formats are supported
by the application.

@param Application $app