} else if (pdfobj.isNumber()) {
// not shown
} else if (pdfobj.isString()) {
// not shown
} else if (pdfobj.isStream()) {
leaf = new StreamTreeNode(pdfobj, "Stream");
node.add(leaf);
leaf = new DictionaryTreeNode("PdfDictionary " + pdfobj,
(PdfDictionary) pdfobj);
node.add(leaf);
Set s = ((PdfDictionary) pdfobj).getKeys();