qstn

from __future__ import annotations

from typing import List, Optional

from pydantic import BaseModel, Field

class AttachedToLeadEntities(BaseModel):
    contacts: List[Contact] = None
    companies: List[Company] = None

class Contact(BaseModel):
    id: int = None
    ...

class Lead(BaseModel):
    id: int = None
    ...
    attached: Optional[AttachedToLeadEntities] = Field(alias="_embedded")

AttachedToLeadEntities.update_forward_refs()