public Role build() throws MetaException {
    if (roleName == null || ownerName == null) {
      throw new MetaException("role name and owner name must be provided.");
    }
    return new Role(roleName, createTime, ownerName);
  }
A builder for {@link Role}.  The roleName and the ownerName must be provided.
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/client/builder/RoleBuilder.java