static <A> A third(L<A> l) {
  return _get(l, 2);
}

static <A> A third(Iterable<A> l) {
  if (l == null) null;
  Iterator<A> it = iterator(l);
  repeat 2 {
    if (!it.hasNext()) null;
    it.next();
  }
  ret it.hasNext() ? it.next() : null;
}

ifclass Producer
static <A> A third(Producer<A> p) {
  if (p == null) null;
  repeat 2 {
    if (p.next() == null) null;
  }
  ret p.next();
}
endif

static <A> A third(A[] bla) {
  ret bla == null || bla.length <= 2 ? null : bla[2];
}

ifclass T3
static <A, B, C> C third(T3<A, B, C> t) {
  ret t == null ? null : t.c;
}
endif