void () { doTest("(a: str, b: bool) -> str", """ from typing import Callable, ParamSpec P = ParamSpec("P") def changes_return_type_to_str(x: Callable[P, int]) -> Callable[P, str]: ... def returns_int(a: str, b: bool) -> int: return 42 expr = changes_return_type_to_str(returns_int)"""); }