static <A> bool containsOneOf(Collection<A> l, A... x) {
  for (A a : unnull(l))
    if (eqOneOf(a, x))
      true;
  false;
}

static <A> bool containsOneOf(Collection<A> l, Set<A> set) {
  if (set == null) false;
  for (A a : unnull(l))
    if (set.contains(a))
      true;
  false;
}