private static <T extends Comparable<?>> int maxLevel(Node node) {
if (node == null) return 0;
return Math.max(BTreePrinter.maxLevel(node.getLeft()), BTreePrinter.maxLevel(node.getRight()))
+ 1;
}
public static <T extends Comparable<?>> void printNode(Node root) {
int maxLevel = BTreePrinter.maxLevel(root);
printNodeInternal(Collections.singletonList(root), 1, maxLevel);
}