@Override
    public SaslAuthMethod getSaslAuthMethod() {
      return SASL_AUTH_METHOD;
    }
Client provider that finds custom Token in the user's UGI and authenticates with the server via
DIGEST-MD5 using that password.
hbase-server/src/test/java/org/apache/hadoop/hbase/security/provider/CustomSaslAuthenticationProviderTestBase.java