/// <summary>
/// Gets all ancestors (parent, grandparent, etc.) and self of the specified <paramref name="node"/> in the hierarchical structure.
/// </summary>
/// <typeparam name="T">The type of the instance represented by the specified <paramref name="node"/> in the hierarchical structure.</typeparam>
/// <param name="node">The node that the hierarchical structure represents.</param>
/// <returns>An <see cref="IEnumerable{T}"/> sequence equal to ancestors and self of the specified <paramref name="node"/>.</returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="node"/> is null.
/// </exception>
public static IEnumerable <IHierarchy <T> > AncestorsAndSelf <T>(this IHierarchy <T> node)
{
Validator.ThrowIfNull(node, nameof(node));
IList <IHierarchy <T> > result = new List <IHierarchy <T> >(HierarchyUtility.WhileSourceTraversalIsNotNull(node, HierarchyUtility.AncestorsAndSelf));
return(result.Count > 0 ? result.Reverse() : node.Yield());
}
