itext7 pdfwriter outputstream csharp

                
                        public byte[] CreatePdf()
    {
        var stream = new MemoryStream();
        var writer = new PdfWriter(stream);
        var pdf = new PdfDocument(writer);
        var document = new Document(pdf);

        document.Add(new Paragraph("Hello world!"));
        document.Close();

        return stream.ToArray();
    }