documentation, if provided along with the Derivative Works; or,
          within a display generated by the Derivative Works, if and
          wherever such third-party notices normally appear. The contents
          of the NOTICE file are for informational purposes only and
          do not modify the License. You may add Your own attribution

        connect0();

        if (LogStream.level >= 3) {
            log.println("queryPath: " + path);
        }

        /* normally we'd check the negotiatedCapabilities for CAP_NT_SMBS
         * however I can't seem to get a good last modified time from
         * SMB_COM_QUERY_INFORMATION so if NT_SMBs are requested

      Parameter param = params.get(i);
      Object arg = args.get(i);
      // Use new fresh value generator because 'args' were populated with new fresh generator each.
      // Two newFreshValueGenerator() instances should normally generate equal value sequence.
      Object shouldBeEqualArg = generateDummyArg(param, newFreshValueGenerator());
      if (arg != shouldBeEqualArg
          && Objects.equals(arg, shouldBeEqualArg)

API 的用户（外部开发者）要在您的 API 内使用 POST 请求创建一条发票记录。

（假设）您的 API 将：

* 把发票发送至外部开发者的消费者
* 归集现金
* 把通知发送至 API 的用户（外部开发者）
    * 通过（从您的 API）发送 POST 请求至外部 API（即**回调**）来完成

## 常规 **FastAPI** 应用 { #the-normal-fastapi-app }

添加回调前，首先看下常规 API 应用是什么样子。

常规 API 应用包含接收 `Invoice` 请求体的*路径操作*，还有包含回调 URL 的查询参数 `callback_url`。

这部分代码很常规，您对绝大多数代码应该都比较熟悉了：

{* ../../docs_src/openapi_callbacks/tutorial001_py310.py hl[7:11,34:51] *}

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          do not modify the License. You may add Your own attribution

          documentation, if provided along with the Derivative Works; or,
          within a display generated by the Derivative Works, if and
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          of the NOTICE file are for informational purposes only and
          do not modify the License. You may add Your own attribution

          documentation, if provided along with the Derivative Works; or,
          within a display generated by the Derivative Works, if and
          wherever such third-party notices normally appear. The contents
          of the NOTICE file are for informational purposes only and
          do not modify the License. You may add Your own attribution

          documentation, if provided along with the Derivative Works; or,
          within a display generated by the Derivative Works, if and
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          do not modify the License. You may add Your own attribution

   *
   * <p>The corresponding root-mean-square error in {@code x} as a function of {@code y} is a
   * fraction {@code sqrt(1/(R*R) - 1)} of the population standard deviation of {@code x}. This fit
   * does not normally minimize that error: to do that, you should swap the roles of {@code x} and
   * {@code y}.
   *
   * <h3>Non-finite values</h3>
   *

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