code: public Credentials getCredentials() {
          if (!Utils.isEmpty(tenant) || !Utils.isEmpty(user)) {
              return new Credentials(tenant, user, password);
          }
          return null;
      }
docs: Return a Credentials object if either tenant or user is set (or both). If neither
  is set, null is returned.
  
  @return  Credentials to use with Client or null if there are no credentials to set.