@Builder
@RequiredArgsConstructor(access = AccessLevel.PRIVATE)
public final class Repo {
  private final Function<String, RevCommit> commitStrategy;

  public Option<RevCommit> commit(String commitMessage) {
    return Option(commitStrategy)
      .onEmpty(() -> log.info("no CommitStrategy defined"))
      .map($ -> $.apply(commitMessage));
  }

  public static Repo Repo(){
    return Repo.builder()
      .commitStrategy(SOME_STATIC_FUNCTION) // or provided via factory args
      .build();
  }

}