public void test(IDocument doc, IProcessingCallback Processing)
        {
            Processing.ReportMessage("Setting fc_Predefined:InvoicePredefinedVendorId from import folder...");

            IPage  page = doc.Pages[0];
            string path = page.ImageSource;

            string pattern = @"\[(.*?)\]";
            Match  m       = Regex.Match(path, pattern, RegexOptions.IgnoreCase);

            Processing.ReportMessage("Testing RegEx...");

            if (m.Success)
            {
                string BUid = m.Groups[1].Value;

                Processing.ReportMessage("Regex succesfull, setting " + BUid + " as the BU ID!");

                doc.Properties.Set("fc_Predefined:InvoicePredefinedVendorId", BUid);
            }
            else
            {
                Processing.ReportWarning("Could not detect BU ID :-(");
            }
        }