How to create an abstract document

[csmsln]

I'm going to define some documents that all of them have the 3 fields: uuid, created_at, modified_at.
I used the following code for inheritance, but the BaseDocument will be created as a separate collection and this makes further errors.
I only need to this BaseDocument be a abstract document not a real one.
Thanks

class BaseDocument(Document):
        uuid: str = Field(default_factory=lambda: str(uuid4()))
        created_at: datetime = Field(default_factory=datetime.utcnow)
        modified_at: datetime | None = None

        class Settings:
            is_root = True


class SampleDocument(BaseDocument):
        name: str

After I try to setup the database and collections, it creates 2 collections: BaseDocument + SampleDocument