VersionID:   "",
				IsLatest:    true,
				NumVersions: 1,
			},
			want: 0,
			lc:   lc,
		},
	}
	for i, tc := range tests {
		t.Run(fmt.Sprintf("test-%d", i+1), func(t *testing.T) {
			if got := tc.lc.FilterRules(tc.opts); len(got) != tc.want {
				t.Fatalf("Expected %d rules to match but got %d", tc.want, len(got))
			}
			w := httptest.NewRecorder()
			tc.lc.SetPredictionHeaders(w, tc.opts)

                is not available, instead of erroring out, the dependency result will
                be `None`.

                This is useful when you want to have optional authentication.

                It is also useful when you want to have authentication that can be
                provided in one of multiple optional ways (for example, with OpenID
                Connect or in a cookie).
                """

				failOnErr(err)
				_, err = hash.Write(data)
				failOnErr(err)
				got[conf] = map[ErasureAlgo]uint64{algo: hash.Sum64()}
			}

			if a, b := want[conf], got[conf]; !reflect.DeepEqual(a, b) {
				fmt.Fprintf(os.Stderr, "%v: error on self-test [d:%d,p:%d]: want %#v, got %#v\n", algo, conf[0], conf[1], a, b)
				ok = false
				continue
			}
			// Delete first shard and reconstruct...
			first := encoded[0]

<img src="/img/tutorial/query-param-models/image01.png">
</div>

## Forbid Extra Query Parameters { #forbid-extra-query-parameters }

In some special use cases (probably not very common), you might want to **restrict** the query parameters that you want to receive.

You can use Pydantic's model configuration to `forbid` any `extra` fields:

{* ../../docs_src/query_param_models/tutorial002_an_py310.py hl[10] *}

## Do not Separate Schemas { #do-not-separate-schemas }

Now, there are some cases where you might want to have the **same schema for input and output**.

Probably the main use case for this is if you already have some autogenerated client code/SDKs and you don't want to update all the autogenerated client code/SDKs yet, you probably will want to do it at some point, but maybe not right now.

			t.Errorf("Test %d: filtered headers do not match expected headers - got: %v , want: %v", i, test.Header, test.ExpectedHeader)
		}
		RemoveSensitiveEntries(metadata)
		if !areKeysEqual(test.ExpectedHeader, metadata) {
			t.Errorf("Test %d: filtered headers do not match expected headers - got: %v , want: %v", i, test.Header, test.ExpectedHeader)
		}
	}

		Ciphertext: key.Ciphertext,
	})
	if err != nil {
		t.Fatalf("Failed to decrypt key: %v", err)
	}
	if !bytes.Equal(key.Plaintext, plaintext) {
		t.Fatalf("Decrypted key does not match generated one: got %x - want %x", key.Plaintext, plaintext)
	}
}

func TestDecryptKey(t *testing.T) {
	KMS, err := ParseSecretKey("my-key:eEm+JI9/q4JhH8QwKvf3LKo4DEBl6QbfvAl1CAbMIv8=")
	if err != nil {

# Development - Contributing

First, you might want to see the basic ways to [help FastAPI and get help](help-fastapi.md).

## Developing

If you already cloned the [fastapi repository](https://github.com/fastapi/fastapi) and you want to deep dive in the code, here are some guidelines to set up your environment.

### Install requirements

Create a virtual environment and install the required packages with [`uv`](https://github.com/astral-sh/uv):

{* ../../docs_src/bigger_applications/app_an_py310/internal/admin.py hl[3] title["app/internal/admin.py"] *}

But we still want to set a custom `prefix` when including the `APIRouter` so that all its *path operations* start with `/admin`, we want to secure it with the `dependencies` we already have for this project, and we want to include `tags` and `responses`.

<div class="screenshot">
<img src="/img/tutorial/header-param-models/image01.png">
</div>

## Forbid Extra Headers { #forbid-extra-headers }

In some special use cases (probably not very common), you might want to **restrict** the headers that you want to receive.

You can use Pydantic's model configuration to `forbid` any `extra` fields:

{* ../../docs_src/header_param_models/tutorial002_an_py310.py hl[10] *}