@Override
  public List<HiveRoleGrant> getPrincipalGrantInfoForRole(String roleName)
      throws HiveAuthzPluginException, HiveAccessControlException {
    // validate
    roleName = roleName.toLowerCase();

    return hiveAccessController.getPrincipalGrantInfoForRole(roleName);
  }
Wrapper for {@link SQLStdHiveAccessController} that does validation of
arguments and then calls the real object. Doing the validation in this
separate class, so that the chances of missing any validation is small.

Validations/Conversions to be done
1. Call SQLAuthorizationUtils.getValidatedPrincipals on HivePrincipal to validate and
update
2. Convert roleName to lower case
ql/src/java/org/apache/hadoop/hive/ql/security/authorization/plugin/sqlstd/SQLStdHiveAccessControllerWrapper.java