@Override
  protected List createChildrenList() {
    // Measurements show that in most situations the number of children is small.
    // Avoid wasting memory by creating ArrayList with the default capacity of 10.
    return new ArrayList(2);
  }
Tag this ASTNode with information about the object from which this node
originated.
parser/src/java/org/apache/hadoop/hive/ql/parse/ASTNode.java