Optional<CertificateAndKey> certificateAndKey() throws CliArgumentsException {
        Path certificateFile = fileValue(CERTIFICATE_OPTION).orElse(null);
        Path privateKeyFile = fileValue(PRIVATE_KEY_OPTION).orElse(null);
        if (privateKeyFile == null && certificateFile == null) return Optional.empty();
        return Optional.of(new CertificateAndKey(certificateFile, privateKeyFile));
    }
Parses command line arguments

@author bjorncs
vespa-feed-client-cli/src/main/java/ai/vespa/feed/client/impl/CliArguments.java