Breaking 05_03 in twain

Ch05/05_04_End/Common/Models/EntityNotFoundException.cs

@@ -0,0 +1,25 @@
+using System;
+
+namespace HPlusSports
+{
+    public class EntityNotFoundException : ApplicationException
+    {
+        public object Id { get; }
+        public Type Type { get; }
+
+        public EntityNotFoundException(Type type, object id)
+          : base($"Entity ${id?.ToString()} of type ${type?.Name} not found.")
+        {
+            Type = type;
+            Id = id;
+        }
+    }
+
+    public class EntityNotFoundException<T> : EntityNotFoundException
+    {
+        public EntityNotFoundException(object id) : base(typeof(T), id)
+        {
+        }
+    }
+
+}