public void saveUser() {
String uuid;
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context);
if (sharedPreferences.contains("uuid")) {
uuid = sharedPreferences.getString("uuid", null);
} else {
uuid = UUID.randomUUID().toString();
sharedPreferences.edit().putString("uuid", uuid).apply();
}
api.saveUser(uuid);
}
