AndroidAuthSession, DropboxException are not recognizable

Hello, I deleted the v1 dropbox sdk from my android app and added 3.0.4. The following things are not recognizable by android studio. Where can I check out what to use intead of (for example) AndroidAuthSession?

Thanks

AndroidAuthSession,

DropboxException

DropboxAPI

private AndroidAuthSession buildSession() throws DropboxException {
    AppKeyPair appKeyPair = new AppKeyPair(APP_KEY, APP_SECRET);
    AndroidAuthSession session = new AndroidAuthSession(appKeyPair);

    session.setOAuth2AccessToken(ACCESSTOKEN);
    return session;
}

AndroidAuthSession session = null;
try {
    session = buildSession();
} catch (DropboxException e) {
    e.printStackTrace();
}
dropboxAPI = new DropboxAPI<>(session);
String[] fnames;
DropboxAPI.Entry dirent = null;
try {
    dirent = dropboxAPI. metadata("/", 1000, null, true, null);
} catch (DropboxException e) {
    e.printStackTrace();
}
ArrayList<DropboxAPI.Entry> files = new ArrayList<>();