text: from typing import Optional
  
  from pydantic import BaseModel
  
  
  # Shared properties
  class ItemBase(BaseModel):
      title: Optional[str] = None
      description: Optional[str] = None
  
  
  # Properties to receive on item creation
  class ItemCreate(ItemBase):
      title: str
  
  
  # Properties to receive on item update
  class ItemUpdate(ItemBase):
      pass
  
  
  # Properties shared by models stored in DB
  class ItemInDBBase(ItemBase):
      id: int
      title: str
      owner_id: int
  
      class Config:
          orm_mode = True
  
  
  # Properties to return to client
  class Item(ItemInDBBase):
      pass
  
  
  # Properties properties stored in DB
  class ItemInDB(ItemInDBBase):
      pass
  