svoid test_structure_stringArrays() {
  S[] a = new { "hello", "world", null };
  
  assertEqualsVerbose([[array S{"hello", "world", null}]], struct(a));
  S[] a2 = restruct(a);
  assertEqualsVerbose(toList(a), toList(a2));
  
  S[][] b = { a };
  assertEqualsVerbose([[array S/2{array S{"hello", "world", null}}]], struct(b));
  S[][] b2 = restruct(b);
  assertEqualsVerbose(lmap toList(b), lmap toList(b2));
}

Began life as a copy of #1031244