Actor Method don't support custom object

[heavenwing]

Expected Behavior

my actor interface defines below:

from abc import abstractmethod

from dapr.actor import ActorInterface, actormethod

from common_models.agent import ReportGuideAgentResult


class ReportGuideAgentActorInterface(ActorInterface):
    @abstractmethod
    @actormethod(name="Answer")
    async def answer(self, user_input: str) -> ReportGuideAgentResult: ...

Actual Behavior

But got a ERR_ACTOR_INVOKE_METHOD error: "ReportGuideAgentResult is not JSON serializable"

I have to change return type into str, and serialize it in my Actor class, and deserialize it in my Client class.

VERSION is 1.15