public void AncestorsFromRoot()
{
var startNode = _tree[1];
var result = HierarchyWalker.Ancestors(startNode, n => n.Parent);
Assert.True(!result.Any());
}
public void Ancestors()
{
var startNode = _tree[1111];
var expectedNodes = new[] { 111, 11, 1 };
var result = HierarchyWalker.Ancestors(startNode, n => n.Parent);
var resultNodes = result.Select(n => n.NodeId).ToList();
Assert.True(expectedNodes.Length == resultNodes.Count);
Assert.True(expectedNodes.All(node => resultNodes.Contains(node)));
}