presto-proxy/src/main/java/io/prestosql/proxy/JsonWebTokenHandler.java/JsonWebTokenHandler/getBearerToken
class JsonWebTokenHandler:    public String getBearerToken(String subject)
    {
        checkState(jwtSigner.isPresent(), "not configured");

        JwtBuilder jwt = Jwts.builder()
                .setSubject(subject)
                .setExpiration(Date.from(ZonedDateTime.now().plusMinutes(5).toInstant()));

        jwtSigner.get().accept(jwt);
        jwtKeyId.ifPresent(keyId -> jwt.setHeaderParam(KEY_ID, keyId));
        jwtIssuer.ifPresent(jwt::setIssuer);
        jwtAudience.ifPresent(jwt::setAudience);

        return jwt.compact();
    }