sbool traits_multiLine = true;

extend Base {
  new L<S> traits;
  bool hasTrait(S t) { ret containsIC(traits(), t); }
  L<S> traits() { if (nempty(text) && neq(first(traits), text)) traits.add(0, text); ret traits; }
  void addTraits(L<S> l) { setAddAll(traits(), l); }
  void addTrait(S t) { if (nempty(t)) setAdd(traits(), t); }
  
  S textForRender() {
    L<S> traits = traits();
    if (traits_multiLine) ret lines(traits);
    if (l(traits) <= 1) ret first(traits);
    ret first(traits) + " [" + join(", ", dropFirst(traits)) + "]";
  }
}