please include function callF.

static O callFOpt_cached(O f, O... args) ctex {
  if (f == null) null;
  if (f instanceof Runnable) { ((Runnable) f).run(); null; }
  if (f instanceof S) ret callOptMC((S) f, args);
  
  Class c = f.getClass();
  ArrayList<Method> methods;
  synchronized(callF_cache) {
    methods = callF_cache.get(c);
    if (methods == null)
      methods = callF_makeCache(c);
  }
  
  int n = l(methods);
  if (n == 0) null;
  if (n == 1) ret methods.get(0).invoke(f, args);
  for i to n: {
    Method m = methods.get(i);
    if (call_checkArgs(m, args, false))
      ret m.invoke(f, args);
  }
  null;
}