public interface TreeContext {
	TreeNode getRoot();

	TreeContext prev();

	string getUuid();

	string getTreeName();

	long getRevision();

	TreeMap<string, TreeMap<string, List<TreeNode>>> getIndex();

    // Iterable<TreeOperation> getOperations();

	// ParentIndex getParentIndex(); do not use, in the game.

	InterfaceTraverser getTraverser();
}