byte[] fullData = concat(messageHeader(3), data);
        InputStream in = new ByteArrayInputStream(fullData);
        SocketInputStream sis = new SocketInputStream(in);

        // Read the three data bytes
        assertEquals(1, sis.read());
        assertEquals(2, sis.read());
        assertEquals(3, sis.read());

        // After consuming all data, trying to read again will attempt to read

///

## Các Kiểu (Types) và Kiểm tra (Validation)

Các biến môi trường có thể chỉ xử lí **chuỗi ký tự**, vì chúng nằm bên ngoài đoạn mã Python và phải tương thích với các chương trình khác và phần còn lại của hệ thống (và thậm chí với các hệ điều hành khác, như Linux, Windows, macOS).

![editor support](https://fastapi.tiangolo.com/img/pycharm-completion.png)

Você terá completação do seu código que você poderia considerar impossível antes. Como por exemplo, a chave `price` dentro do corpo JSON (que poderia ter sido aninhado) que vem de uma requisição.

		}
	}
}

// TraceHandler sends http trace messages back to peer rest client
func (s *peerRESTServer) TraceHandler(ctx context.Context, payload []byte, _ <-chan []byte, out chan<- []byte) *grid.RemoteErr {
	var traceOpts madmin.ServiceTraceOpts
	err := json.Unmarshal(payload, &traceOpts)
	if err != nil {
		return grid.NewRemoteErr(err)
	}
	var wg sync.WaitGroup

              [INFO] Validating units:
              [INFO]    Ignored 53 units with compilation errors in first pass.
              [INFO] Compile with -strict or with -logLevel set to TRACE or DEBUG to see all errors.

            Turning up the log level, we see that GWT is trying to compile classes from other
            packages, like RangeTest. The reason for this is that GWT doesn't distinguish between

{* ../../docs_src/python_types/tutorial008.py hl[1,4] *}


이 뜻은 아래와 같습니다:

* 변수 `prices`는 `dict`이다:
    * `dict`의 키(key)는 `str`타입이다. (각 아이템의 이름(name))
    * `dict`의 값(value)는 `float`타입이다. (각 아이템의 가격(price))

#### `Optional`

`str`과 같이 타입을 선언할 때 `Optional`을 쓸 수도 있는데, "선택적(Optional)"이기때문에 `None`도 될 수 있습니다:

```Python hl_lines="1  4"
{!../../docs_src/python_types/tutorial009.py!}
```

    @DisplayName("Should produce consistent keys for same input")
    void testDeriveKeys_Consistency() {
        // Given
        int dialect = Smb2Constants.SMB2_DIALECT_0311;

        // When - derive same key twice
        byte[] signingKey1 = Smb3KeyDerivation.deriveSigningKey(dialect, sessionKey, preauthIntegrity);
        byte[] signingKey2 = Smb3KeyDerivation.deriveSigningKey(dialect, sessionKey, preauthIntegrity);

  /*
   * Since Quantiles provides a fluent-style API, each test covers a chain of methods resulting in
   * the computation of one or more quantiles (or in an error) rather than individual methods. The
   * tests are divided into three sections:
   * 1. Tests on a hardcoded dataset for chains starting with median(), quartiles(), and scale(10);
   * 2. Tests on hardcoded datasets include non-finite values for chains starting with scale(10);

  /*
   * Since Quantiles provides a fluent-style API, each test covers a chain of methods resulting in
   * the computation of one or more quantiles (or in an error) rather than individual methods. The
   * tests are divided into three sections:
   * 1. Tests on a hardcoded dataset for chains starting with median(), quartiles(), and scale(10);
   * 2. Tests on hardcoded datasets include non-finite values for chains starting with scale(10);

            final int n = readBytesWireFormat(buffer, bufferIndex);
            if (n != this.byteCount && log.isTraceEnabled()) {
                log.trace("Short read, have " + n + ", want " + this.byteCount);
            }
            bufferIndex += this.byteCount;
        }

        /*
         * if there is an andx and it itself is an andx then just recur by