@pytest.mark.parametrize(
    "path,headers,expected_status,expected_response",
    [
        ("/items", None, 200, {"User-Agent": "testclient"}),
        ("/items", {"X-Header": "notvalid"}, 200, {"User-Agent": "testclient"}),
        ("/items", {"User-Agent": "FastAPI test"}, 200, {"User-Agent": "FastAPI test"}),
    ],
)
def test(path, headers, expected_status, expected_response, client: TestClient):

                        "x_tag": [],
                        "accept": "*/*",
                        "accept-encoding": "gzip, deflate",
                        "connection": "keep-alive",
                        "user-agent": "testclient",
                        "save-data": "true",
                        "if-modified-since": "yesterday",
                        "x-tag": ["one", "two"],
                    },
                }
            ]

    if out_path.exists():
        print(f"Found existing translation: {out_path}")
        old_translation = out_path.read_text(encoding="utf-8")
    print(f"Translating {en_path} to {language} ({language_name})")
    agent = Agent("openai:gpt-5.2")

    prompt_segments = [
        general_prompt,
        lang_prompt_content,
    ]
    if old_translation:
        prompt_segments.extend(
            [

                        "host": "testserver",
                        "accept": "*/*",
                        "accept-encoding": "gzip, deflate",
                        "connection": "keep-alive",
                        "user-agent": "testclient",
                    },
                }
            ]
        }
    )


def test_header_param_model_extra(client: TestClient):
    response = client.get(

* 📝 Add link to New Relic article: "How to monitor FastAPI application performance using Python agent". PR [#5260](https://github.com/tiangolo/fastapi/pull/5260) by [@sjyothi54](https://github.com/sjyothi54).