此处，`shutdown` 事件处理器函数在 `log.txt` 中写入一行文本 `Application shutdown`。

/// info | 说明

`open()` 函数中，`mode="a"` 指的是**追加**。因此这行文本会添加在文件已有内容之后，不会覆盖之前的内容。

///

/// tip | 提示

注意，本例使用 Python `open()` 标准函数与文件交互。

这个函数执行 I/O（输入/输出）操作，需要等待内容写进磁盘。

但 `open()` 函数不支持使用 `async` 与 `await`。

因此，声明事件处理函数要使用 `def`，不能使用 `asnyc def`。

///

### `startup` 和 `shutdown` 一起使用

        // Arrange
        SmbPipeOutputStream out = newStream();
        CIFSException boom = new CIFSException("open-fail");
        when(handle.ensureOpen()).thenThrow(boom);

        // Act + Assert
        CIFSException ex = assertThrows(CIFSException.class, out::ensureOpen);
        assertEquals("open-fail", ex.getMessage());
        verify(handle, times(1)).ensureOpen();
    }

    @Test

        this.wildcard = wildcard;
        this.nameFilter = filter;
        this.searchAttributes = searchAttributes;

        this.treeHandle = th.acquire();
        try {
            this.next = open();
            if (this.next == null) {
                doClose();
            }
        } catch (final Exception e) {
            doClose();
            throw e;
        }

    }

    /**

  }

  @SuppressWarnings({"removal", "Finalize"}) // b/260137033
  @Override
  protected void finalize() {
    if (state.get().equals(OPEN)) {
      logger.get().log(SEVERE, "Uh oh! An open ClosingFuture has leaked and will close: {0}", this);
      FluentFuture<V> unused = finishToFuture();
    }
  }

  public void write(int b) throws IOException {
    hasher.putByte((byte) b);
    out.write(b);
  }

  @Override
  public void write(byte[] bytes, int off, int len) throws IOException {
    hasher.putBytes(bytes, off, len);
    out.write(bytes, off, len);
  }

  /**
   * Returns the {@link HashCode} based on the data written to this stream. The result is

        return 0;
    }

    @Override
    int readSetupWireFormat(final byte[] buffer, final int bufferIndex, final int len) {
        return 0;
    }

    @Override
    int readParametersWireFormat(final byte[] buffer, int bufferIndex, final int len) {
        available = readInt2(buffer, bufferIndex);
        bufferIndex += 2;
        int head = readInt2(buffer, bufferIndex);
        bufferIndex += 2;

        return 0;
    }

    @Override
    int readParametersWireFormat(final byte[] buffer, final int bufferIndex, final int len) {
        return 0;
    }

    @Override
    int readDataWireFormat(final byte[] buffer, final int bufferIndex, final int len) {
        return 0;
    }

    @Override
    public String toString() {
        return ("TransWaitNamedPipe[" + super.toString() + ",pipeName=" + name + "]");

		if er.readN == 0 && Equal(etag, er.checksum) {
			return er
		}
	}
	if len(forceMD5) != 0 {
		return &Reader{
			src:      r,
			md5:      NewUUIDHash(forceMD5),
			checksum: etag,
		}
	}
	return &Reader{
		src:      r,
		md5:      md5.New(),
		checksum: etag,
	}
}

// Read reads up to len(p) bytes from the underlying
// io.Reader as specified by the io.Reader interface.

				case "FileHeaderInfo":
					s = strings.ToLower(s)
					if len(s) != 0 {
						if s != none && s != use && s != ignore {
							return errors.New("unsupported FileHeaderInfo")
						}
						args.FileHeaderInfo = s
					}

				case "RecordDelimiter":
					if len(s) != 0 {
						args.RecordDelimiter = s
					}
				case "FieldDelimiter":
					if len(s) != 0 {
						args.FieldDelimiter = s
					}

			return nil, false, errIndexLookup
		}

		if idx >= len(arr) {
			return nil, false, nil
		}
		return jsonpathEval(p[1:], arr[idx])

	case p[0].ObjectWildcard:
		switch kvs := v.(type) {
		case jstream.KVS:
			if len(p[1:]) > 0 {
				return nil, false, errWildcardObjectUsageInvalid
			}

			return kvs, false, nil
		case simdjson.Object:
			if len(p[1:]) > 0 {
				return nil, false, errWildcardObjectUsageInvalid