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* 。

                    // skip
                    continue;
                }
                try {
                    final String[] permissions = split(getValue(list, 2), ",").get(stream -> stream.map(permissionHelper::encode)
                            .filter(StringUtil::isNotBlank).distinct().toArray(n -> new String[n]));
                    final String[] labels = split(getValue(list, 3), ",")

            final PermissionHelper permissionHelper = ComponentUtil.getPermissionHelper();
            entity.setPermissions(split(form.permissions, "\n").get(stream -> stream.map(s -> permissionHelper.encode(s))
                    .filter(StringUtil::isNotBlank).distinct().toArray(n -> new String[n])));
            entity.setVirtualHosts(split(form.virtualHosts, "\n")

            final PermissionHelper permissionHelper = ComponentUtil.getPermissionHelper();
            entity.setPermissions(split(form.permissions, "\n").get(stream -> stream.map(s -> permissionHelper.encode(s))
                    .filter(StringUtil::isNotBlank).distinct().toArray(n -> new String[n])));
            entity.setVirtualHosts(split(form.virtualHosts, "\n")

  }

  public void testToString() {
    byte[] data = new byte[] {127, -128, 5, -1, 14};
    assertEquals("7f8005ff0e", HashCode.fromBytes(data).toString());
    assertEquals("7f8005ff0e", base16().lowerCase().encode(data));
  }

  public void testHashCode_nulls() throws Exception {
    sanityTester().testNulls();
  }

  public void testHashCode_equalsAndSerializable() throws Exception {

        NdrBuffer buf = new NdrBuffer(out, 0);

        msg.flags = DCERPC_FIRST_FRAG | DCERPC_LAST_FRAG;
        msg.call_id = call_id.incrementAndGet();

        msg.encode(buf);

        if ( this.securityProvider != null ) {
            buf.setIndex(0);
            this.securityProvider.wrap(buf);
        }
        return buf;
    }


    /**
     * 

 * Mappings may overlap.
 *
 * ASCII-Only
 * ==========
 *
 * Neither the section index nor the ranges data use bit 0x80 anywhere. That means the data is
 * strictly ASCII. This is intended to make it efficient to encode this data as a string, and to
 * index into it as a string.
 *
 * The mappings data contains non-ASCII characters.
 */
internal class IdnaMappingTable internal constructor(
  val sections: String,

`FastAPI` 🤙 🎧-🎓 `Starlette`. , 🚥 👆 ⏪ 💭 ⚖️ ⚙️ 💃, 🌅 🛠️ 🔜 👷 🎏 🌌.

⏮️ **FastAPI** 👆 🤚 🌐 **💃**'Ⓜ ⚒ (FastAPI 💃 🔛 💊):

* 🤙 🎆 🎭. ⚫️ <a href="https://github.com/encode/starlette#performance" class="external-link" target="_blank">1️⃣ ⏩ 🐍 🛠️ 💪, 🔛 🇷🇪 ⏮️ **✳** &amp; **🚶**</a>.
* ** *️⃣ ** 🐕‍🦺.
* -🛠️ 🖥 📋.
* 🕴 &amp; 🤫 🎉.
* 💯 👩‍💻 🏗 🔛 🇸🇲.
* **⚜**, 🗜, 🎻 📁, 🎏 📨.

		query := url.Values{}
		for key, value := range testCase.queryParams {
			query.Set(key, value)
		}

		// Create a request to use.
		req, e := http.NewRequest(http.MethodGet, "http://host/a/b?"+query.Encode(), nil)
		if e != nil {
			t.Errorf("(%d) failed to create http.Request, got %v", i, e)
		}

		// Do the same for the headers.
		for key, value := range testCase.headers {
			req.Header.Set(key, value)
		}

{!../../docs_src/body/tutorial004.py!}
```

Os parâmetros da função serão reconhecidos conforme abaixo:

* Se o parâmetro também é declarado na **rota**, será utilizado como um parâmetro de rota.
* Se o parâmetro é de um **tipo único** (como `int`, `float`, `str`, `bool`, etc) será interpretado como um parâmetro de **consulta**.
* Se o parâmetro é declarado como um **modelo Pydantic**, será interpretado como o **corpo** da requisição.

/// note | "Observação"