mypyc: Bad float type var in subtype

things.py

from abc import ABC, abstractmethod
from typing import Any, Generic, TypeVar

# from numbers import Real

T = TypeVar("T")


class JsonAdapter(ABC, Generic[T]):
    @abstractmethod
    def encode(self, obj: T) -> Any:
        pass

    @abstractmethod
    def decode(self, obj: Any) -> T:
        pass


class IntJsonAdapter(JsonAdapter[int]):
    def encode(self, obj: int) -> int:
        if not isinstance(obj, int):
            raise TypeError("Object is not an int")
        return obj

    def decode(self, obj: Any) -> int:
        return int(obj)


# class FloatJsonAdapter(JsonAdapter[float]):
#     def encode(self, obj: float) -> float:
#         if not isinstance(obj, float):
#             raise TypeError("Object is not a Real")
#         return obj

#     def decode(self, obj: Any) -> float:
#         return float(obj)


class FloatJsonAdapter(JsonAdapter[Any]):
    def encode(self, obj: Any) -> Any:
        if not isinstance(obj, float):
            raise TypeError("Object is not a Real")
        return obj

    def decode(self, obj: Any) -> Any:
        return float(obj)