`UploadFile` tem os seguintes métodos `assíncronos`. Todos eles chamam os métodos de arquivo correspondentes por baixo dos panos (usando o `SpooledTemporaryFile` interno).

* `write(data)`: Escreve `data` (`str` ou `bytes`) no arquivo.
* `read(size)`: Lê `size` (`int`) bytes/caracteres do arquivo.
* `seek(offset)`: Vai para o byte na posição `offset` (`int`) no arquivo.

from typing_extensions import Annotated

app = FastAPI()


class FormData(BaseModel):
    username: str
    password: str


@app.post("/login/")
async def login(data: Annotated[FormData, Form()]):

		return nil, nil, err
	}
	data = buf
	if data.validate() != nil {
		data.repair()
	}

	return meta, data, nil
}

type xlMetaV2ShallowVersion struct {
	header xlMetaV2VersionHeader
	meta   []byte
}

//msgp:ignore xlMetaV2 xlMetaV2ShallowVersion

type xlMetaV2 struct {
	versions []xlMetaV2ShallowVersion

	// data will contain raw data if any.

		version == xlMetaVersion100) &&
		format == xlMetaFormat)
}

// Verifies if the backend format metadata is sane by validating
// the ErasureInfo, i.e. data and parity blocks.
func isXLMetaErasureInfoValid(data, parity int) bool {
	return ((data >= parity) && (data > 0) && (parity >= 0))
}

//msgp:clearomitted

//go:generate msgp -file=$GOFILE -unexported

// A xlMetaV1Object represents `xl.meta` metadata header.

        accessTokenPager.clear();
        return asHtml(path_AdminAccesstoken_AdminAccesstokenJsp).renderWith(data -> {
            searchPaging(data, form);
        });
    }

    protected void searchPaging(final RenderData data, final SearchForm form) {
        RenderDataUtil.register(data, "accessTokenItems", accessTokenService.getAccessTokenList(accessTokenPager)); // page navi

        // restore from pager

And in the code, we get a `dict` with all the data sent by the client, **only the data sent by the client**, excluding any values that would be there just for being the default values. To do it we use `exclude_unset=True`. This is the main trick. 🪄

Then we use `hero_db.sqlmodel_update(hero_data)` to update the `hero_db` with the data from `hero_data`.

    * If you didn't use FastAPI and used Starlette directly (or another tool, like Sanic, Flask, Responder, etc) you would have to implement all the data validation and serialization yourself. So, your final application would...

    await manager.connect(websocket)
    try:
        while True:
            data = await websocket.receive_text()
            await manager.send_personal_message(f"You wrote: {data}", websocket)
            await manager.broadcast(f"Client #{client_id} says: {data}")
    except WebSocketDisconnect:
        manager.disconnect(websocket)

			if err != nil {
				t.Errorf("error opening test data file: %v", err)
			}
			defer configDumpFile.Close()
			configDump, err := io.ReadAll(configDumpFile)
			if err != nil {
				t.Errorf("error reading test data file: %v", err)
			}

			outFile, err := os.Open(fmt.Sprintf("testdata/secret/%s/output", tc.sds))
			if err != nil {
				t.Errorf("error opening test data output file: %v", err)
			}
			defer outFile.Close()

        byte[] seqBytes = new byte[4];
        SMBUtil.writeInt4(seqNum, seqBytes, 0);

        MessageDigest mac = Crypto.getHMACT64(sk);
        mac.update(seqBytes); // sequence
        mac.update(data); // data
        byte[] dgst = mac.digest();
        byte[] trunc = new byte[8];
        System.arraycopy(dgst, 0, trunc, 0, 8);

        if ( log.isDebugEnabled() ) {