from abc import ABC, abstractmethod

class A[T](ABC):
    @abstractmethod
    async def get(self) -> T: ...

class B(A[int], ABC):
    @abstractmethod
    async def get_specific(self): ...

class C:
    pass

class D(C, B):
    async def get(self):
        return 1
    async def get_specific(self):
        return 2

print(D.__orig_bases__) # (__main__.A[int], <class 'abc.ABC'>)
print(D.__bases__)      # (<class '__main__.C'>, <class '__main__.B'>)