@Override
    public String toString() {
      return MoreObjects.toStringHelper(this).add("snapshotIdOrRefName", snapshotIdOrRefName).toString();
    }
Value object class, that stores the set snapshot version operation specific parameters
<ul>
  <li>snapshot Id: it should be a valid snapshot version or a SnapshotRef name</li>
</ul>
ql/src/java/org/apache/hadoop/hive/ql/parse/AlterTableExecuteSpec.java