相同类型在MyPy中如何不兼容？

Question

带有以下示例：

from typing import Callable, Generic, Type, TypeVar

ThetaType = TypeVar('ThetaType', bound=int)
XType = TypeVar('XType', bound=int)


class IteratedFunction(Generic[ThetaType, XType]):

    def find_fixed_point(self,
                         theta: ThetaType,
                         x_init: XType) -> XType:
        return x_init


def combinator(
    iterated_function_cls: Type[
        IteratedFunction[ThetaType, XType]]) -> Callable[
            [IteratedFunction[ThetaType, XType]], XType]:
    old_find_fixed_point = iterated_function_cls.find_fixed_point

    def new_find_fixed_point(
            iterated_function: IteratedFunction[ThetaType, XType],
            theta: ThetaType,
            x_init: XType) -> XType:
        return old_find_fixed_point(iterated_function, theta, x_init)

    return new_find_fixed_point

MyPy说：

a.py:25: error: Incompatible return value type (got "XType", expected "XType")
a.py:25: error: Argument 1 has incompatible type "IteratedFunction[ThetaType, XType]"; expected "IteratedFunction[ThetaType, XType]"
a.py:25: error: Argument 2 has incompatible type "ThetaType"; expected "ThetaType"
a.py:25: error: Argument 3 has incompatible type "XType"; expected "XType"
a.py:27: error: Incompatible return value type (got "Callable[[IteratedFunction[ThetaType, XType], ThetaType, XType], XType]", expected "Callable[[IteratedFunction[ThetaType, XType]], XType]")

Answer 1

我不确定我是否同意这个问题的前提。