from typing import Callable
from dataclasses import dataclass

@dataclass
class Box[T]:
    item: T

type RefBox[T] = Box[T]

def transmute_inner[T, V](x: RefBox[T]) -> RefBox[V]:
    # Expected: Return type does not match returned value: expected `RefBox[V@transmute_inner]`, found `RefBox[T@transmute_inner]`
    # Actual: Return type does not match returned value: expected `main.RefBox @ main.py:8:6[V@transmute_inner]`, found `main.RefBox @ main.py:8:6[T@transmute_inner]` 
    return x