docs: public PublicKey getServerKey(){
          logger.debug("getServerKey()");
          try {
              if(serverPublicKey!=null) return serverPublicKey;
  
              byte[] pubKey = getWebService().getPublicKey();
              logger.debug("pubKey: " + String.valueOf(pubKey));
              serverPublicKey = Crypto.pubKeyFromBytes(pubKey);
              return serverPublicKey;
          } catch (Exception e) {
              logger.error("Failed to getServerKey()", e);
          }
  
          return null;
      }