static int indexOfSearchingFromMiddleIC(L<S> l, S s) {
  int len = l(l), middle = len/2;
  for n to middle: {
    int i = middle-n;
    if (i >= 0 && eqic(l.get(i), s)) ret i;
    i = middle+n+1;
    if (i < len && eqic(l.get(i), s)) ret i;
  }
  ret -1;
}