static OnePathWithOrigin g22_regionOutline(IImageRegion region) {
  // TODO: optimize
  L<PtBuffer> outlines = region.createdWithDiagonals()
    ? g22_allBorderTraces_withDiagonals(region)
    : g22_allBorderTraces(region);
    
  ret new OnePathWithOrigin(first(outlines), false);
}