how to hide pdf form field with IText 7

Question

I tried to hidden a form field in pdf using latest Itext 7, but could not find any solution.

I've searched the web, got example like that:

using (PdfReader reader = new PdfReader(src))
{
    using (PdfStamper stamper = new PdfStamper(reader, new FileStream(dest, FileMode.Create)))
    {
        AcroFields form = stamper.AcroFields;
        form.SetFieldProperty("fieldName", "setflags", PdfAnnotation.FLAGS_HIDDEN, null);
        stamper.FormFlattening = true;
    }
}

It seems api is not working now.

Someone said PdfFormField had method setVisibility(), but I also does not find it.