Renamed the project to Umbraco.PublishedCache.NuCache - and move non NuCache related stuff to abstractions and infrastructure.

src/Umbraco.PublishedCache.NuCache/Navigable/Source.cs

@@ -0,0 +1,33 @@
+using System.Linq;
+using Umbraco.Core.Xml.XPath;
+
+namespace Umbraco.Web.PublishedCache.NuCache.Navigable
+{
+    internal class Source : INavigableSource
+    {
+        private readonly INavigableData _data;
+        private readonly bool _preview;
+        private readonly RootContent _root;
+
+        public Source(INavigableData data, bool preview)
+        {
+            _data = data;
+            _preview = preview;
+
+            var contentAtRoot = data.GetAtRoot(preview);
+            _root = new RootContent(contentAtRoot.Select(x => x.Id));
+        }
+
+        public INavigableContent Get(int id)
+        {
+            // wrap in a navigable content
+
+            var content = _data.GetById(_preview, id);
+            return content == null ? null : new NavigableContent(content);
+        }
+
+        public int LastAttributeIndex => NavigableContentType.BuiltinProperties.Length - 1;
+
+        public INavigableContent Root => _root;
+    }
+}