///|
fn @colour.PdfContentColour::pdf_tweak_fill_op(
  self : @colour.PdfContentColour,
) -> @content.PdfContentOp {
  match self {
    PdfContentGrey(grey) => Op_g(grey)
    PdfContentRGB(red, green, blue) => Op_rg(red, green, blue)
    PdfContentCMYK(cyan, magenta, yellow, black) =>
      Op_k(cyan, magenta, yellow, black)
  }
}

///|
fn @colour.PdfContentColour::pdf_tweak_stroke_op(
  self : @colour.PdfContentColour,
) -> @content.PdfContentOp {
  match self {
    PdfContentGrey(grey) => Op_G(grey)
    PdfContentRGB(red, green, blue) => Op_RG(red, green, blue)
    PdfContentCMYK(cyan, magenta, yellow, black) =>
      Op_K(cyan, magenta, yellow, black)
  }
}