/// <summary>
/// Get ancestor categories.
/// </summary>
/// <param name="entryContent">The entry content.</param>
/// <param name="contentLoader">The content loader.</param>
/// <returns>Collection of category content.</returns>
public static IEnumerable <NodeContent> GetAncestorCategories(
this EntryContentBase entryContent, IContentLoader contentLoader)
{
return(entryContent.GetCategories()
.SelectMany(parentLink =>
contentLoader.GetAncestors(parentLink)
.OfType <NodeContent>()
.Concat(new[] { contentLoader.Get <NodeContent>(parentLink) }))
.Distinct(new NodeContentComparer()));
}