Implement interface

Author: davidwengier

src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/Cohost/CohostRoslynRenameTest.cs

@@ -202,7 +202,10 @@ internal void SetInvoker(TestRemoteServiceInvoker remoteServiceInvoker)
             _remoteServiceInvoker = remoteServiceInvoker;
         }
 
+        public ValueTask InitializeAsync() => throw new NotImplementedException();
+
         public ValueTask<TResult?> TryInvokeAsync<TService, TResult>(Solution solution, Func<TService, RazorPinnedSolutionInfoWrapper, CancellationToken, ValueTask<TResult>> invocation, CancellationToken cancellationToken, [CallerFilePath] string? callerFilePath = null, [CallerMemberName] string? callerMemberName = null) where TService : class
             => _remoteServiceInvoker.AssumeNotNull().TryInvokeAsync(solution, invocation, cancellationToken, callerFilePath, callerMemberName);
+
     }
 }