sS structure_checkForProblems(O a) {
  S s = structure(a);
  int i = indexOfAnonymousClassInStruct(s);
  if (i >= 0)
    fail("Anonymous class found in struct at " + i + "/" + l(s) + ": " + substringWithEllipsis(s, i-50, i+50));
  ret s;
}