@Override
  public List<String> get_role_names() throws TException {
    incrementCounter("get_role_names");
    firePreEvent(new PreAuthorizationCallEvent(this));
    List<String> ret;
    try {
      ret = getMS().listRoleNames();
      return ret;
    } catch (Exception e) {
      throw handleException(e).throwIfInstance(MetaException.class).defaultRuntimeException();
    }
  }
Check if newRole is in parent hierarchy of curRole
@param newRole
@param curRole
@return true if newRole is curRole or present in its hierarchy
@throws MetaException
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/HMSHandler.java