B4J Question Read the value of a check box in a PDF File

Sub ExportXFDF(path As String, filename As String, xfdffilename As String)
    Log($"PDF2XFDF"$)
    Private box As PDFBox
    box.Initialize("",File.Combine(path,filename))
    Dim doc As PDDocument = box.Document
    Dim cat As PDDocumentCatalog = doc.DocumentCatalog
    Dim acroform As PDAcroForm = cat.AcroForm
    Dim fdfdoc As FDFDocument = acroform.exportFDF
    fdfdoc.saveXFDF(xfdffilename)
    doc.close()    ' Close PDF
    fdfdoc.close
End Sub
Sub ImportXFDF(path As String, filename As String, xfdffilename As String, destinationpdfFilename As String)
    Private box As PDFBox
    box.Initialize("",File.Combine(path,filename))
    Dim doc As PDDocument = box.Document
    Dim cat As PDDocumentCatalog = doc.DocumentCatalog
    Dim acroform As PDAcroForm = cat.AcroForm
    Dim fdfdoc As FDFDocument = acroform.exportFDF
    fdfdoc.loadXFDF(xfdffilename)
    acroform.importFDF(fdfdoc)
    fdfdoc.close
    doc.save(destinationpdfFilename)    ' Save PDF to Disc
    doc.close()    ' Close PDF
    
End Sub