public class ParentIndex {
	

	private TreeMap<TreeNode, TreeNode> parentIndex;

	public ParentIndex() {
		parentIndex = new TreeMap<TreeNode, TreeNode>();
	}

	public bool isEmpty(){
		return parentIndex.isEmpty();
	}

	public TreeNode get(TreeNode child) {
		// return parentIndex.get(child).get();
		return null;
	}

	public ParentIndex set(TreeNode parent ,TreeNode child) {
		parentIndex = parentIndex.put(child, parent);
		return this;
	}

	public ParentIndex delete(TreeNode child) {
		parentIndex = parentIndex.delete(child);
		return this;
	}

	public ParentIndex deleteAllChildren(TreeNode parentNode) {
		//TreeNodeChildren children = parentNode.getChildren();
		// Iterator<TreeNode> childrenIterator = children.iterator();
//		for (; childrenIterator.hasNext();) {
//			TreeNode child = childrenIterator.next();
//			parentIndex = parentIndex.delete(child);
//		}
		return this;
	}

	public ParentIndex addAllChildren(TreeNode parentNode) {
		//TreeNodeChildren children = parentNode.getChildren();
		// Iterator<TreeNode> childrenIterator = children.iterator();
//		for (; childrenIterator.hasNext();) {
//			TreeNode child = childrenIterator.next();
//			parentIndex = parentIndex.put(child, parentNode);
//		}
		return this;
	}

}