private async Task <Document> GetChangedSuppressionDocumentAsync(CancellationToken cancellationToken) { var suppressionsDoc = await GetOrCreateSuppressionsDocumentAsync(_document, cancellationToken).ConfigureAwait(false); var suppressionsRoot = await suppressionsDoc.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false); var newSuppressionsRoot = _fixer.AddGlobalSuppressMessageAttribute(suppressionsRoot, _targetSymbol, _diagnostic); return(suppressionsDoc.WithSyntaxRoot(newSuppressionsRoot)); }