please include function callOpt_cached.

static O call_withVarargs(O o, S method, O... args) ctex {
  if (o == null) null;
  
  if (o instanceof Class) {
    Class c = (Class) o;
    _MethodCache cache = callOpt_getCache(c);
    
    Method me = cache.findMethod(method, args);
    if (me == null) {
      // TODO: varargs
      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)
      ret invokeMethod(me, o, args);
      
    // try varargs
    L<Method> methods = cache.cache.get(method);
    if (methods != null) methodSearch: for (Method m : methods) {
      continue unless m.isVarArgs();
      Class<?>[] types = m.getParameterTypes();
      int n = types.length-1, nArgs = args.length;
      continue unless nArgs >= n;
      for i to n:
        if (!argumentCompatibleWithType(arg, types[i]))
          continue methodSearch;
      Class varArgType = types[n].getComponentType();
      for (int i = n; i < nArgs; i++)
        if (!argumentCompatibleWithType(arg, varArgType))
          continue methodSearch;
      O[] newArgs = new O[n+1];
      arrayCopy(args, 0, newArgs, 0, n);
      O[] varArgs = arrayOfType(varArgType, nArgs-n);
      arrayCopy(args, n, varArgs, 0, nArgs-n);
      newArgs[n] = varArgs;
      ret invokeMethod(me, o, newArgs);
    }
  }
    findVarargsMethodInCache(cache, method, args);
      fail("Method " + c.getName() + "." + method + "(" + joinWithComma(classNames(args)) + ") not found");
  }
}