The following code runs fine, but mypy produce an error: ``` python from typing import List class Foo(object): def __init__(self): self.version = [1, 2, 3] def __getitem__(self, k): return self.version[k] def list_foo(f): # type: (Foo) -> List[int] return list(f) print list_foo(Foo()) ``` ``` example.py: note: In function "list_foo": example.py:13: error: No overload variant of "list" matches argument types [example.Foo] Fail ```