concept Bla {
  new Ref<Bla> ref;
}

svoid test_findBackRefs() {
  new Concepts cc;
  Bla a = cnew(cc, Bla);
  Bla b = cnew(cc, Bla, ref := a);
  assertEqualsVerbose(ll(b), findBackRefs Bla(a));
  cset(b, ref := null);
  assertEqualsVerbose(ll(), findBackRefs Bla(a));
  cset(a, ref := b);
  assertEqualsVerbose(ll(a), findBackRefs Bla(b));
  cdelete(a);
  assertEqualsVerbose(ll(), findBackRefs Bla(b));
}