AFAICT, there's no reason links _has_ to be empty and not null

Author: andrewlock

Datadog.Trace.Minimal.slnf

@@ -2,15 +2,20 @@
   "solution": {
     "path": "Datadog.Trace.sln",
     "projects": [
+      "tracer\\src\\Datadog.Trace.Annotations\\Datadog.Trace.Annotations.csproj",
       "tracer\\src\\Datadog.Trace.ClrProfiler.Managed.Loader\\Datadog.Trace.ClrProfiler.Managed.Loader.csproj",
+      "tracer\\src\\Datadog.Trace.Manual\\Datadog.Trace.Manual.csproj",
       "tracer\\src\\Datadog.Trace.MSBuild\\Datadog.Trace.MSBuild.csproj",
       "tracer\\src\\Datadog.Trace.SourceGenerators\\Datadog.Trace.SourceGenerators.csproj",
       "tracer\\src\\Datadog.Trace.Tools.Analyzers.CodeFixes\\Datadog.Trace.Tools.Analyzers.CodeFixes.csproj",
       "tracer\\src\\Datadog.Trace.Tools.Analyzers\\Datadog.Trace.Tools.Analyzers.csproj",
       "tracer\\src\\Datadog.Tracer.Native\\Datadog.Tracer.Native.DLL.vcxproj",
       "tracer\\src\\Datadog.Tracer.Native\\Datadog.Tracer.Native.vcxproj",
       "tracer\\src\\Datadog.Trace\\Datadog.Trace.csproj",
-      "tracer\\test\\Datadog.Trace.SourceGenerators.Tests\\Datadog.Trace.SourceGenerators.Tests.csproj"
+      "tracer\\test\\benchmarks\\Benchmarks.Trace\\Benchmarks.Trace.csproj",
+      "tracer\\test\\Datadog.Trace.SourceGenerators.Tests\\Datadog.Trace.SourceGenerators.Tests.csproj",
+      "tracer\\test\\Datadog.Trace.TestHelpers\\Datadog.Trace.TestHelpers.csproj",
+      "tracer\\test\\Datadog.Trace.Tests\\Datadog.Trace.Tests.csproj"
     ]
   }
 }

tracer/test/Datadog.Trace.Tests/Propagators/MultiSpanContextPropagatorTests.cs

@@ -404,7 +404,7 @@ public void Extract_Behavior_Continue()
                       opts => opts.ExcludingMissingMembers());
 
             result.Baggage.Should().BeNull();
-            result.Links.Should().BeEmpty();
+            result.Links.Should().BeNullOrEmpty();
         }
 
         [Fact]