static <A> A call(O o) {
  return (A) callF(o);
}

// varargs assignment fixer for a single string array argument
static <A> A call(O o, S method, S[] arg) {
  return call(o, method, new O[] {arg});
}

static <A> A call(O o, S method, O... args) {
  ret (A) call_cached(o, method, args);
}