internal void WriteTo()
{
var dic = new PdfDictionary();
dic.Put(PdfName.Fields, Calculate(_fdf._fields));
if (_fdf.File != null)
{
dic.Put(PdfName.F, new PdfString(_fdf.File, PdfObject.TEXT_UNICODE));
}
var fd = new PdfDictionary();
fd.Put(PdfName.Fdf, dic);
var refi = AddToBody(fd).IndirectReference;
var b = GetIsoBytes("trailer\n");
((DocWriter)this).Os.Write(b, 0, b.Length);
var trailer = new PdfDictionary();
trailer.Put(PdfName.Root, refi);
trailer.ToPdf(null, ((DocWriter)this).Os);
b = GetIsoBytes("\n%%EOF\n");
((DocWriter)this).Os.Write(b, 0, b.Length);
((DocWriter)this).Os.Dispose();
}