private void findMixins(Type t, Hashtable acc)
{
// if mixin I haven't seen add to accumulator
string qname = t.qname();
if (t.isMixin() && acc[qname] == null)
acc[qname] = t;
// recurse
for (int i=0; i<t.mixins().sz(); ++i)
findMixins((Type)t.mixins().get(i), acc);
}
