Add Quadtree.Count

Quadtree/Quadtree.cs

@@ -11,7 +11,6 @@ namespace SpatialCollections
     /// </summary>
     // TODO: Support for moving objects without having to remove and re-add them.
     // TODO: Add method to prune empty leaves. An empty leaf is not removed automatically when its last object is removed.
-    // TODO: Add unit tests.
     public class Quadtree
     {
         // TODO: It should be possible to calculate whether average query time will be better with or without split, without resorting to max leaf size and max tree depth.
@@ -67,6 +66,8 @@ namespace SpatialCollections
             _vertexStack = new Stack<int>();
         }
 
+        public int Count => _items.Count;
+
         public void Add(IWorldObject obj)
         {
             var itemIndex = _items.Count;