from pydantic import BaseModel

class Item(BaseModel):
    name: str
    price: Optional[float] = None
    owner_ids: Optional[List[int]] = None

app = FastAPI()

@app.get("/items/invalidnone", response_model=Union[Item, None])
def get_invalid_none():
    return None
```

</p>

<p>
The form <code>a … b</code> represents the set of characters from
<code>a</code> through <code>b</code> as alternatives. The horizontal
ellipsis <code>…</code> is also used elsewhere in the spec to informally denote various
enumerations or code snippets that are not further specified. The character <code>…</code>
(as opposed to the three characters <code>...</code>) is not a token of the Go
language.
</p>

<p>