@Explain(displayName = "owner principal", explainLevels = { Level.USER, Level.DEFAULT, Level.EXTENDED })
  public PrincipalDesc getOwnerPrincipal() {
    return ownerPrincipal;
  }
DDL task description for ALTER TABLE ... SET OWNER ... commands.
ql/src/java/org/apache/hadoop/hive/ql/ddl/table/misc/owner/AlterTableSetOwnerDesc.java