class TransportManager {

    public TransportClient getCurrentTransportClientOrThrow(String caller)
            throws TransportNotRegisteredException {
        if (mCurrentTransportName == null) {
            throw new IllegalStateException("No transport selected");
        }
        synchronized (mTransportLock) {
            return getTransportClientOrThrow(mCurrentTransportName, caller);
        }
    }

      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);

}