code: @Override
      public Callback[] getRequiredCallbacks(CallbackHandler callbackHandler) throws IOException, UnsupportedCallbackException {
          Callback[] callbacks = new Callback[3];
          callbacks[0] = new WSCredTokenCallbackImpl("Credential Token");
          callbacks[1] = new WSAuthMechOidCallbackImpl("AuthMechOid");
          callbacks[2] = new JwtTokenCallback();
          callbackHandler.handle(callbacks);
          return callbacks;
      }
docs: Gets the required Callback objects needed by this login module.
  
  @param callbackHandler
  @return
  @throws IOException
  @throws UnsupportedCallbackException