svoid test_str_shortenSynthetic() {
  testFunctionValues str_shortenSynthetic(
    (IF1) x -> x, "Synthetic instance of interface IF1",
    "bla", "bla",
    null, "null",
    new IF1 { public O get(O o) { ret o; } toString { ret "test"; } }, "test",
  );
}

Began life as a copy of #1030053