code: @Override
      public void processChallenge(String challenge) throws MalformedChallengeException {
          // Parse Challenge Data
          // Challenge is base64 string to be given to gss context
          if (StringUtils.hasText(challenge)) {
              // Remove leading auth scheme name and trim data
              this.challenge = challenge.substring(EsHadoopAuthPolicies.NEGOTIATE.length()).trim();
          }
      }
docs: {@inheritDoc}
  <p>
  Called using the challenge text parsed from the header that is associated with this scheme's name.
  May advance the authentication process across multiple calls.
  </p>