assert items == {"foo": {"name": "Fighters"}, "bar": {"name": "Tenders"}}

        response = client.get("/items/foo")
        assert response.status_code == 200
        assert response.json() == {"name": "Fighters"}

        # After the requests is done, the items are still there
        assert items == {"foo": {"name": "Fighters"}, "bar": {"name": "Tenders"}}

from typing import Union

from fastapi import Body, FastAPI, status
from fastapi.responses import JSONResponse

app = FastAPI()

items = {"foo": {"name": "Fighters", "size": 6}, "bar": {"name": "Tenders", "size": 3}}


@app.put("/items/{item_id}")
async def upsert_item(
    item_id: str,
    name: Union[str, None] = Body(default=None),
    size: Union[int, None] = Body(default=None),
):
    if item_id in items:

from fastapi.testclient import TestClient

app = FastAPI()

items = {}


@app.on_event("startup")
async def startup_event():
    items["foo"] = {"name": "Fighters"}
    items["bar"] = {"name": "Tenders"}


@app.get("/items/{item_id}")
async def read_items(item_id: str):
    return items[item_id]


def test_read_items():
    with TestClient(app) as client:
        response = client.get("/items/foo")

from fastapi import FastAPI

app = FastAPI()

items = {}


@app.on_event("startup")
async def startup_event():
    items["foo"] = {"name": "Fighters"}
    items["bar"] = {"name": "Tenders"}


@app.get("/items/{item_id}")
async def read_items(item_id: str):

        200: {
            "description": "Item requested by ID",
            "content": {
                "application/json": {
                    "example": {"id": "bar", "value": "The bar tenders"}
                }
            },
        },
    },
)
async def read_item(item_id: str):
    if item_id == "foo":
        return {"id": "foo", "value": "there goes my hero"}
    else:

                                    "example": {
                                        "id": "bar",
                                        "value": "The bar tenders",
                                    },
                                }
                            },
                        },
                        "422": {

    @JvmName("of")
    fun Map<String, String>.toHeaders(): Headers = commonToHeaders()

    @JvmName("-deprecated_of")
    @Deprecated(
      message = "function moved to extension",
      replaceWith = ReplaceWith(expression = "headers.toHeaders()"),
      level = DeprecationLevel.ERROR,
    )
    fun of(headers: Map<String, String>): Headers = headers.toHeaders()
  }

	AmzMetaUnencryptedContentLength = "X-Amz-Meta-X-Amz-Unencrypted-Content-Length"
	AmzMetaUnencryptedContentMD5    = "X-Amz-Meta-X-Amz-Unencrypted-Content-Md5"

	// AWS server-side encryption headers for SSE-S3, SSE-KMS and SSE-C.
	AmzServerSideEncryption                      = "X-Amz-Server-Side-Encryption"
	AmzServerSideEncryptionKmsID                 = AmzServerSideEncryption + "-Aws-Kms-Key-Id"

And as the `Response` can be used frequently to set headers and cookies, **FastAPI** also provides it at `fastapi.Response`.

///

## Custom Headers { #custom-headers }

Keep in mind that custom proprietary headers can be added <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">using the `X-` prefix</a>.

///

## Cabeçalhos personalizados { #custom-headers }

Tenha em mente que cabeçalhos personalizados proprietários podem ser adicionados <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">usando o prefixo `X-`</a>.