docs: public static Jose4jRsaJWK getInstance(String alg, String use, PublicKey publicKey, PrivateKey privateKey, String kid) {
  
          //String kid = RandomUtils.getRandomAlphaNumeric(KID_LENGTH);
          RSAPublicKey pubKey = (RSAPublicKey) publicKey;
          RSAPrivateKey priKey = (RSAPrivateKey) privateKey;
          Jose4jRsaJWK jwk = new Jose4jRsaJWK(pubKey);
  
          jwk.setPrivateKey(priKey);
          jwk.setAlgorithm(alg);
          jwk.setKeyId(kid);
          jwk.setUse(use == null ? JwkConstants.sig : use);
  
          return jwk;
      }