please include function callOpt_cached.

static O call_cached(O o, S method, O... args) ctex {
  if (o == null) null;
  
  if (o instanceof Class) {
    Class c = (Class) o;
    _MethodCache cache = callOpt_getCache(c);
    
    // TODO: (super-rare) case where method exists static and non-static
    // with different args
    
    Method me = cache.findMethod(method, args);
    if (me == null)
      fail("Method " + c.getName() + "." + method + "(" + joinWithComma(classNames(args)) + ") not found");
    if ((me.getModifiers() & Modifier.STATIC) == 0)
      fail("Method " + c.getName() + "." + method + "(" + joinWithComma(classNames(args)) + ") not static");
    ret invokeMethod(me, null, args);
  } else {
    Class c = o.getClass();
    _MethodCache cache = callOpt_getCache(c);

    Method me = cache.findMethod(method, args);
    if (me == null)
      fail("Method " + c.getName() + "." + method + "(" + joinWithComma(classNames(args)) + ") not found");
    ret invokeMethod(me, o, args);
  }
}

Began life as a copy of #1018497