getGraphics method
This returns a PdfGraphics object, which can then be used to render on to this page. If a previous PdfGraphics object was used, this object is appended to the page, and will be drawn over the top of any previous objects.
Implementation
PdfGraphics getGraphics() {
final stream = PdfObjectStream(pdfDocument);
final g = PdfGraphics(this, stream.buf);
_contentGraphics[stream] = g;
contents.add(stream);
return g;
}