testReverse(new byte[] {}, new byte[] {});
    testReverse(new byte[] {1}, new byte[] {1});
    testReverse(new byte[] {1, 2}, new byte[] {2, 1});
    testReverse(new byte[] {3, 1, 1}, new byte[] {1, 1, 3});
    testReverse(new byte[] {-1, 1, -2, 2}, new byte[] {2, -2, 1, -1});
  }

  private static void testReverse(byte[] input, byte[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);

        // Verify ASCII conversion
        byte[] descrBytes = descr.getBytes("ASCII");
        assertNotNull(descrBytes);
        assertEquals(13, descrBytes.length); // WrLeh(5) + null(1) + B13BWz(6) + null(1) = 13
    }

    @Test
    @DisplayName("Test writeSetupWireFormat returns 0")
    void testWriteSetupWireFormat() {
        netShareEnum = new NetShareEnum(realConfig);
        byte[] dst = new byte[100];

        src[srcIndex + 16] = 0x00; // hex code
        src[srcIndex + 17] = (byte) 0xFE; // All flags except one: 11111110
        // Bit 7: group (1)
        // Bits 6-5: owner node type (11 = 3)
        // Bit 4: being deleted (1)
        // Bit 3: in conflict (1)
        // Bit 2: active (1)
        // Bit 1: permanent (1)

        // MAC address

      expected[i] = 5300224;
    }
    // 97-111 are all 2342912
    for (int i = 97; i <= 111; i++) {
      expected[i] = 2342912;
    }
    // 113-117 are all 1048576
    for (int i = 113; i <= 117; i++) {
      expected[i] = 1048576;
    }
    // One offs
    expected[112] = 786432;
    expected[118] = 786432;
    expected[119] = 1048576;
    expected[120] = 458752;

{!../../docs_src/events/tutorial003.py!}
```

这个函数在 `yield`之前的部分，会在应用启动前执行。

剩下的部分在 `yield` 之后，会在应用完成后执行。

## 异步上下文管理器

如你所见，这个函数有一个装饰器 `@asynccontextmanager` 。

它将函数转化为所谓的“**异步上下文管理器**”。

```Python hl_lines="1  13"
{!../../docs_src/events/tutorial003.py!}
```

在 Python 中，  **上下文管理器**是一个你可以在 `with` 语句中使用的东西，例如，`open()` 可以作为上下文管理器使用。

```Python
with open("file.txt") as file:
    file.read()
```

    testReverse(new char[] {}, new char[] {});
    testReverse(new char[] {'1'}, new char[] {'1'});
    testReverse(new char[] {'1', '2'}, new char[] {'2', '1'});
    testReverse(new char[] {'3', '1', '1'}, new char[] {'1', '1', '3'});
    testReverse(new char[] {'A', '1', 'B', '2'}, new char[] {'2', 'B', '1', 'A'});
  }

  private static void testReverse(char[] input, char[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);

  @GwtIncompatible // java.math.BigInteger
  public void testMean() {
    // Odd-sized ranges have an obvious mean
    assertMean(2, 1, 3);

    assertMean(-2, -3, -1);
    assertMean(0, -1, 1);
    assertMean(1, -1, 3);
    assertMean((1 << 30) - 1, -1, Integer.MAX_VALUE);

    // Even-sized ranges should prefer the lower mean
    assertMean(2, 1, 4);
    assertMean(-3, -4, -1);
    assertMean(0, -1, 2);

    testReverse(new double[] {}, new double[] {});
    testReverse(new double[] {1}, new double[] {1});
    testReverse(new double[] {1, 2}, new double[] {2, 1});
    testReverse(new double[] {3, 1, 1}, new double[] {1, 1, 3});
    testReverse(new double[] {-1, 1, -2, 2}, new double[] {2, -2, 1, -1});
  }

  private static void testReverse(double[] input, double[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);

pkg debug/elf, const R_ARM_PREL31 = 42
pkg debug/elf, const R_ARM_PREL31 R_ARM
pkg debug/elf, const R_ARM_PRIVATE_0 = 112
pkg debug/elf, const R_ARM_PRIVATE_0 R_ARM
pkg debug/elf, const R_ARM_PRIVATE_1 = 113
pkg debug/elf, const R_ARM_PRIVATE_1 R_ARM
pkg debug/elf, const R_ARM_PRIVATE_10 = 122
pkg debug/elf, const R_ARM_PRIVATE_10 R_ARM
pkg debug/elf, const R_ARM_PRIVATE_11 = 123
pkg debug/elf, const R_ARM_PRIVATE_11 R_ARM

- github.com/aws/aws-sdk-go-v2/internal/ini: [v1.8.0](https://github.com/aws/aws-sdk-go-v2/tree/internal/ini/v1.8.0)
- github.com/aws/aws-sdk-go-v2/service/internal/accept-encoding: [v1.11.3](https://github.com/aws/aws-sdk-go-v2/tree/service/internal/accept-encoding/v1.11.3)
- github.com/aws/aws-sdk-go-v2/service/internal/presigned-url: [v1.11.15](https://github.com/aws/aws-sdk-go-v2/tree/service/internal/presigned-url/v1.11.15)