I’m looking for the correct way to type hint this collection of generic classes with generic methods. Here is a simplified (non-working) version:

from __future__ import annotations

import typing as t

TypeT = t.TypeVar('TypeT')  # generic type not bound to anything

class BaseR(t.Generic[TypeT]):
  ...

TypeR = t.TypeVar('TypeR', bound=BaseR)  # upper bound at BaseR
TypeE = t.TypeVar('TypeE')  # generic method variable

class BaseU(t.Generic[TypeR]):
  def do_something(self, var: TypeE) -> TypeR[TypeE]:
    ...

class SpecificR(BaseR[TypeT]):
  ...

class SpecificU(BaseU[SpecificR]):
  ...

SpecificU().do_something(1)  # I want this static type to show SpecificR[int] 

Why does the static typing not resolve correctly?