Fix assemblyInfo

src/Logging/Logging.EventSource/test/AssemblyInfo.cs

@@ -1,5 +1,10 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using Xunit;
+
+// There can only be one EventSource per AppDomain, and when an event is raised through that EventSource,
 // all existing listeners that enabled that EventSource will receive the event.
 // This makes running EventSourceLogger tests in parallel difficult. We mark this assembly
 // with CollectionBehavior.CollectionPerAssembly to ensure that all tests in this assembly are executed serially.
-
 [assembly: CollectionBehavior(CollectionBehavior.CollectionPerAssembly)]