class KerberosServerAction extends AbstractServerAction {

  @SuppressWarnings("unchecked")
  protected static Map<String, String> getPrincipalPasswordMap(Map<String, Object> requestSharedDataContext) {
    if (requestSharedDataContext == null) {
      return null;
    } 
    Object map = requestSharedDataContext.computeIfAbsent(PRINCIPAL_PASSWORD_MAP, k -> new HashMap<String, String>());
    return (Map<String, String>) map;
  }

}