# Header Parameter Models { #header-parameter-models }

If you have a group of related **header parameters**, you can create a **Pydantic model** to declare them.

This would allow you to **re-use the model** in **multiple places** and also to declare validations and metadata for all the parameters at once. 😎

/// note

This is supported since FastAPI version `0.115.0`. 🤓

///

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// tip | Astuce

Le deuxième argument de [`os.getenv()`](https://docs.python.org/3.8/library/os.html#os.getenv) est la valeur par défaut à retourner.

S'il n'est pas fourni, c'est `None` par défaut ; ici, nous fournissons `"World"` comme valeur par défaut à utiliser.

///

  }

  @Override public void onOpen(WebSocket webSocket, Response response) {
    webSocket.send("Hello...");
    webSocket.send("...World!");
    webSocket.send(ByteString.decodeHex("deadbeef"));
    webSocket.close(1000, "Goodbye, World!");
  }

  @Override public void onMessage(WebSocket webSocket, String text) {
    System.out.println("MESSAGE: " + text);
  }

b.io/okhttp/5.x/okhttp/okhttp3/-tls-version/) and [cipher suites](https://square.github.io/okhttp/5.x/okhttp/okhttp3/-cipher-suite/) to offer. A client that wants to maximize connectivity would include obsolete TLS versions and weak-by-design cipher suites. A strict client that wants to maximize security would be limited to only the latest TLS version and strongest cipher suites.

Specific security vs. connectivity decisions are implemented by [ConnectionSpec](https://square.github.io/ok...

     * @throws IllegalArgumentException if {@code edge} already exists in the network and does not
     *     connect {@code nodeU} to {@code nodeV}
     * @throws IllegalArgumentException if the introduction of the edge would violate {@link
     *     #allowsParallelEdges()} or {@link #allowsSelfLoops()}
     */
    @CanIgnoreReturnValue
    public ImmutableNetwork.Builder<N, E> addEdge(N nodeU, N nodeV, E edge) {

     */
    @Test
    void testSuccessfulHandshake() throws IOException, SecurityException {
        // This test is simplified to verify basic handshake behavior
        // Full NTLM handshake testing would require more complex mocking

        // Arrange - Mock a server that supports NTLM
        mockResponse(HTTP_UNAUTHORIZED, "Unauthorized", Collections.singletonMap("WWW-Authenticate", Collections.singletonList("NTLM")),

						all = append(all, recDst)
					}
				}()
				if err != nil {
					in.err = err
				}
				// We don't need the input any more.
				//nolint:staticcheck // SA6002 Using pointer would allocate more since we would have to copy slice header before taking a pointer.
				r.bufferPool.Put(in.input)
				in.input = nil
				in.dst <- all
			}
		}()
	}
	return nil
}

router_b_a = APIRouter()
router_b_a_c_override = APIRouter()  # Overrides default class again


@app.get("/")
def get_root():
    return {"msg": "Hello World"}


@app.get("/override", response_class=PlainTextResponse)
def get_path_override():
    return "Hello World"


@router_a.get("/")
def get_a():
    return {"msg": "Hello A"}


@router_a.get("/override", response_class=PlainTextResponse)

    }

    @Test
    public void test_buildFunctionScoreQuery_multiWordQuery() {
        QueryBuilder innerQuery = request.buildQuery("hello world", Collections.emptyList());
        QueryBuilder result = request.buildFunctionScoreQuery("hello world", innerQuery);

        assertNotNull(result);
        assertTrue(result instanceof FunctionScoreQueryBuilder);

        String queryString = result.toString();

        assertTrue(pacCredentialType.isCredentialTypeCorrect());
    }

    /**
     * Tests the isCredentialTypeCorrect method with a null byte array.
     * This test is indirect as the constructor would throw an exception.
     * We can't instantiate the class with null, so we can't directly test this method's behavior with null.
     * However, the constructor logic `!isCredentialTypeCorrect()` covers this.