from typing import _T as T, Callable, Generic, TypeVar

class A(Generic[T]):
    def f(self) -> None: ...

c: Callable[[A[int]], None]
c = A.f
c = A[int].f  # error: Incompatible types in assignment (expression has type "(A[T]) -> None", variable has type "(A[int]) -> None") 

class B(A[int]): ...

# some higher order method
foo(list_of_b, B.f)  # error