Implement ISourceNode on Base

src/Benchmarks/SerializationBenchmarks.cs

@@ -44,13 +44,17 @@ public string XmlDictionarySerializer()
         [Benchmark]
         public string TypedElementSerializerJson()
         {
+#pragma warning disable SDK0001
             return Patient.ToTypedElement().ToJson();
+#pragma warning restore SDK0001
         }
 
         [Benchmark]
         public string TypedElementSerializerXml()
         {
+#pragma warning disable SDK0001
             return Patient.ToTypedElement().ToXml();
+#pragma warning restore SDK0001
         }
     }
 }

src/Hl7.Fhir.Base/ElementModel/PocoBuilderExtensions.cs

@@ -10,7 +10,9 @@
 using Hl7.Fhir.Introspection;
 using Hl7.Fhir.Model;
 using Hl7.Fhir.Serialization;
+using Hl7.Fhir.Utility;
 using System;
+using System.Diagnostics.CodeAnalysis;
 
 namespace Hl7.Fhir.ElementModel
 {
@@ -28,8 +30,12 @@ public static T ToPoco<T>(this ITypedElement element, ModelInspector inspector,
         public static Base ToPoco(this ITypedElement element, ModelInspector inspector, PocoBuilderSettings settings = null) =>
                new NewPocoBuilder(inspector, settings ?? new PocoBuilderSettings()).BuildFrom(element);
 
-        public static ISourceNode ToSourceNode(this Base @base, ModelInspector inspector, string rootName = null) =>
-                @base.ToTypedElement(inspector, rootName).ToSourceNode();
-
+        public static ISourceNode ToSourceNode(this Base @base, ModelInspector inspector, string rootName = null)
+        {
+            var node = @base.ToElementNode(rootName);
+            ((IAnnotatable)node).AddAnnotation(inspector);
+
+            return node;
+        }
     }
 }