static O[] paramsWithout(O[] a1, O... keys) {
  if (l(a1) == 1 && a1[0] instanceof Map)
    ret new O[] { mapMinus((Map) a1[0], keys) };
    
  Set set = lithashset(keys);
  new L l;
  int n = l(a1);
  for (int i = 0; i < n; i += 2)
    if (i == n-1) l.add(a1[i]);
    else if (!set.contains(a1[i])) {
      l.add(a1[i]);
      l.add(a1[i+1]);
    }
  ret toObjectArray(l);
}