private static void addRetrieveParams(@NonNull final Parameters params, @NonNull final OCApiConnector connector) {
        params.add("retr_method", METHOD_RETRIEVE_CACHES);
        params.add("retr_params", "{\"fields\": \"" + getCoreFields(connector) + "\"}");
        params.add("wrap", "true");
    }
Return a pipe-separated list of preferred languages. English and the device default language (if different) will
always be in the list. A user-set language will be first (if set).
main/src/main/java/cgeo/geocaching/connector/oc/OkapiClient.java