public enum Storage {
    DROPBOX("dropbox");

    private final String storageAsString;

    Storage(String storageAsString) {
        this.storageAsString = storageAsString;
    }

    public Optional<Storage> of(String storage) {
        for (Storage value : values()) {
            if (value.storageAsString.equals(storage)) {
                return Optional.of(value);
            }
        }
        return Optional.empty();
    }
}