private Optional<byte[]> readFile() {
        try {
            return Optional.of(Files.readAllBytes(path));
        } catch (NoSuchFileException e) {
            return Optional.empty();
        } catch (IOException e) {
            throw new UncheckedIOException(e);
        }
    }
Java API for a flag database stored in a single file

@author hakonhall
flags/src/main/java/com/yahoo/vespa/flags/file/FlagDbFile.java