svoid test_OnePathShifter() {
  // path going right
  var path = new OnePathShifter(OnePathWithOrigin("4444"), true)!;
  assertEqualsVerbose(str(OnePathWithOrigin(0, 1, "4444")), str(path));
  
  // up, then right (yields only one point)
  path = new OnePathShifter(OnePathWithOrigin("24"), true)!;
  assertEqualsVerbose(str(OnePathWithOrigin(1, 0, "")), str(path));
}