@Throws(IOException::class)
      fun writeByteString(data: ByteString) {
        if (useCompression && Huffman.encodedLength(data) < data.size) {
          val huffmanBuffer = Buffer()
          Huffman.encode(data, huffmanBuffer)
          val huffmanBytes = huffmanBuffer.readByteString()
          writeInt(huffmanBytes.size, PREFIX_7_BITS, 0x80)
          out.write(huffmanBytes)
        } else {

					Idx:      idx,
					Header:   b,
					Metadata: buf.Bytes(),
				}
				return nil
			})
			if e != nil {
				return nil, e
			}
			enc := json.NewEncoder(buf)
			if e := enc.Encode(struct {
				Versions []version
			}{Versions: versions}); e != nil {
				return nil, e
			}
			data = b
		default:
			return nil, fmt.Errorf("unknown metadata version %d", minor)
		}

다음의 스폰서가 될 수 있습니다

* <a href="https://github.com/sponsors/samuelcolvin" class="external-link" target="_blank">Samuel Colvin (Pydantic)</a>
* <a href="https://github.com/sponsors/encode" class="external-link" target="_blank">Encode (Starlette, Uvicorn)</a>

---

Приклад автодоповнення у редакторах:

* у <a href="https://code.visualstudio.com/" class="external-link" target="_blank">Visual Studio Code</a>:

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

* у <a href="https://www.jetbrains.com/pycharm/" class="external-link" target="_blank">PyCharm</a>:

Vous devrez rarement revenir à la documentation.

Voici comment votre éditeur peut vous aider:

* dans <a href="https://code.visualstudio.com/" class="external-link" target="_blank">Visual Studio Code</a>:

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

* dans <a href="https://www.jetbrains.com/pycharm/" class="external-link" target="_blank">PyCharm</a>:

	// always emitted. The legacy MS-DOS date field is encoded according to the
	// location of the Modified time.
	Modified time.Time

	// ModifiedTime is an MS-DOS-encoded time.
	//
	// Deprecated: Use Modified instead.
	ModifiedTime uint16

	// ModifiedDate is an MS-DOS-encoded date.
	//
	// Deprecated: Use Modified instead.
	ModifiedDate uint16

        }

        /**
         * Get the source node for move operations
         *
         * @return source node name
         */
        public String getSourceNode() {
            return sourceNode;
        }

        /**
         * Sets the source node for move operations.
         *
         * @param sourceNode the name of the source node in a share move operation
         */

        final File targetDir = new File(userDir, "target");
        return new File(targetDir, "logs").getAbsolutePath();
    }

    /**
     * Encodes a URL path for filtering.
     *
     * @param path The path to encode.
     * @return The encoded path.
     */
    public String encodeUrlFilter(final String path) {
        if (filterPathEncoding == null || path == null) {
            return path;
        }

因此，我们下一步要做的就是添加代码，为从 API 接收回调的*外部 API*存档。

这部分文档在 `/docs` 下的 Swagger API 文档中显示，并且会告诉外部开发者如何构建*外部 API*。

本例没有实现回调本身（只是一行代码），只有文档部分。

/// tip | 提示

实际的回调只是 HTTP 请求。

实现回调时，要使用 <a href="https://www.encode.io/httpx/" class="external-link" target="_blank">HTTPX</a> 或 <a href="https://requests.readthedocs.io/" class="external-link" target="_blank">Requests</a>。

///

## 编写回调文档代码

应用不执行这部分代码，只是用它来*记录 外部 API* 。

		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(s3Error), r.URL)
		return
	}

	prefix, keyMarker, uploadIDMarker, delimiter, maxUploads, encodingType, errCode := getBucketMultipartResources(r.Form)
	if errCode != ErrNone {
		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(errCode), r.URL)
		return
	}

	if maxUploads < 0 {
		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrInvalidMaxUploads), r.URL)
		return
	}