code: protected boolean validateToken(SignedJWT jwtToken) {
          boolean isValid = validateSignature(jwtToken);
  
          if (isValid) {
              isValid = validateExpiration(jwtToken);
              if (!isValid) {
                  LOG.warn("Expiration time validation of JWT token failed.");
              }
          } else {
              LOG.warn("Signature of JWT token could not be verified. Please check the public key");
          }
          return isValid;
      }
docs: This method provides a single method for validating the JWT for use in
  request processing. It provides for the override of specific aspects of
  this implementation through submethods used within but also allows for
  the override of the entire token validation algorithm.
  
  @param jwtToken the token to validate
  @return true if valid