class TransportManager {

    ComponentName[] getRegisteredTransportComponents() {
        synchronized (mTransportLock) {
            return mRegisteredTransportsDescriptionMap
                    .keySet()
                    .toArray(new ComponentName[mRegisteredTransportsDescriptionMap.size()]);
        }
    }

      TransportManager(@UserIdInt int userId, Context context, Set<ComponentName> whitelist,
            String selectedTransport);
    @VisibleForTesting  TransportManager(
            @UserIdInt int userId,
            Context context,
            Set<ComponentName> whitelist,
            String selectedTransport,
            TransportClientManager transportClientManager);

}