) {
        for (registrar in registrars) {
            if (lock.readLock().withLock { application.isRegistrarRegistered(registrar) }) {
                continue
            }

            lock.writeLock().withLock {
                if (application.isRegistrarRegistered(registrar)) return@withLock
                registrar.register()
                application.serviceRegistered[registrar::class] = true