old_contents: from typing import Optional, Set
  
  from fastapi import FastAPI
  from pydantic import BaseModel, HttpUrl
  
  app = FastAPI()
  
  
  class Image(BaseModel):
      url: HttpUrl
      name: str
  
  
  class Item(BaseModel):
      name: str
      description: Optional[str] = None
      price: float
      tax: Optional[float] = None
      tags: Set[str] = []
      image: Optional[Image] = None
  
  
  @app.put("/items/{item_id}")
  async def update_item(item_id: int, item: Item):
      results = {"item_id": item_id, "item": item}
      return results
  
new_contents: from typing import Optional, Set
  
  from fastapi import FastAPI
  from pydantic import BaseModel, HttpUrl
  
  app = FastAPI()
  
  
  class Image(BaseModel):
      url: HttpUrl
      name: str
  
  
  class Item(BaseModel):
      name: str
      description: Optional[str] = None
      price: float
      tax: Optional[float] = None
      tags: Set[str] = set()
      image: Optional[Image] = None
  
  
  @app.put("/items/{item_id}")
  async def update_item(item_id: int, item: Item):
      results = {"item_id": item_id, "item": item}
      return results
  
subject: Fix tags's declare