/** Make the given child the new parent. */
public void enterChild(int index) {
currentChild = currentParent.getChild();
while ((currentChild != null) && (index != 0)) {
index--;
currentChild = currentChild.getSibling();
}
if (currentChild != null) {
currentParent = currentChild;
currentChild = currentParent.getChild();
}
}
public void next() {
currentChild = currentChild.getSibling();
}