src/AbstractServiceProvider.php
protected function setupUserDetection(Client $client, Application $app)
    {
        try {
            $tokens = $app['security.token_storage'];
            $checker = $app['security.authorization_checker'];
        } catch (InvalidArgumentException $e) {
            return;
        }

        $client->registerCallback(new CustomUser(function () use ($tokens, $checker) {
            $token = $tokens->getToken();

            if (!$token || !$checker->isGranted('IS_AUTHENTICATED_REMEMBERED')) {
                return;
            }

            $user = $token->getUser();

            if ($user instanceof UserInterface) {
                return ['id' => $user->getUsername()];
            }

            return ['id' => (string) $user];
        }));
    }
protected function setupUserDetection(Client $client, Application $app)
    {
        try {
            $tokens = $app['security.token_storage'];
            $checker = $app['security.authorization_checker'];
        } catch (InvalidArgumentException $e) {
            return;
        }

        $client->registerCallback(new CustomUser(function () use ($tokens, $checker) {
            $token = $tokens->getToken();

            if (!$token || !$checker->isGranted('IS_AUTHENTICATED_REMEMBERED')) {
                return;
            }

            $user = $token->getUser();

            if ($user instanceof UserInterface) {
                return ['id' => $user->getUsername()];
            }

            return ['id' => (string) $user];
        }));
    }
Setup user detection.

@param \Bugsnag\Client    $client
@param \Silex\Application $app

@return void