///|
fn PdfDrawRenderState::register_xobject(
  self : PdfDrawRenderState,
  source_name : String,
  prefix : String,
  object_number : Int,
) -> PdfName {
  let resource_name = self.fresh_name(prefix)
  for index in 0.. PdfName {
  let resource_name = self.fresh_name("/X")
  for index in 0..