async function AddPackage(doc, file, desc) {
	const files = await PDFNet.NameTree.create(doc.getSDFDoc(), "EmbeddedFiles");
	const fs = await PDFNet.FileSpec.create(doc, file, true);
	var key = new TextEncoder("utf-8").encode(file);
	files.put(key, fs.getSDFObj());
	fs.getSDFObj().putText("Desc", desc);

	var collection = doc.getRoot().findObj("Collection");
	if (!collection) collection = doc.getRoot().putDict("Collection");

	// You could here manipulate any entry in the Collection dictionary.
		// For example, the following line sets the tile mode for initial view mode
	// Please refer to section '2.3.5 Collections' in PDF Reference for details.
	collection.putName("View", "T");
}

async function main() {
	var doc = await PDFNet.PDFDoc.create();
	await AddPackage(doc, filename, "PDF");
	await AddPackage(doc, imagename, "Image");
}
PDFNet.runWithCleanup(main);