private void validateRole(String roleName) throws NoSuchObjectException {
    // if grantee is a role, check if it exists
    MRole granteeRole = getMRole(roleName);
    if (granteeRole == null) {
      throw new NoSuchObjectException("Role " + roleName + " does not exist");
    }
  }
Verify that role with given name exists, if not throw exception
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/ObjectStore.java