private void OnWorkspaceChanged(object sender, WorkspaceChangeEventArgs changeEvent)
        {
            if (changeEvent.Kind == WorkspaceChangeKind.DocumentChanged)
            {
                var newDocument = changeEvent.NewSolution.GetDocument(changeEvent.DocumentId);

                this.EmitDiagnostics(newDocument.FilePath);
                foreach (var document in _workspace.GetOpenDocumentIds().Select(x => _workspace.CurrentSolution.GetDocument(x)))
                {
                    this.EmitDiagnostics(document.FilePath);
                }
            }
        }