Attribute.java

@Getter
@RequiredArgsConstructor
public enum Attribute {
    NAME("name"),
    COUNTRY("country"),
    LOCALE("locale"),
    EMAIL_ADDRESS("email");

    private final String key;

    public static Optional<Attribute> from(final String key) {
        return Arrays.stream(Attribute.values())
                     .filter(a -> a.getKey().equalsIgnoreCase(key))
                     .findAny();
    }
}