protected internal PdfStructTreeController(PdfReader reader, PdfCopy writer)
{
if (!writer.IsTagged())
throw new BadPdfFormatException(MessageLocalization.GetComposedMessage("no.structtreeroot.found"));
this.writer = writer;
structureTreeRoot = writer.StructureTreeRoot;
structureTreeRoot.Put(PdfName.PARENTTREE, new PdfDictionary(PdfName.STRUCTELEM));
SetReader(reader);
}