assertTrue(mockService.hasRegistration(reg1));
        assertTrue(mockService.hasRegistration(reg2));
        assertTrue(mockService.hasRegistration(reg3));

        // Unregister one
        assertTrue(mockService.unregisterWitness(reg2));
        assertEquals(2, mockService.getRegistrationCount());
        assertFalse(mockService.hasRegistration(reg2));

        // Clean up remaining

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *

          emulator-options: >
            -no-window
            -gpu swiftshader_indirect
            -noaudio
            -no-boot-anim
            -camera-back none
            -memory 2048
          disable-animations: true
          script: echo "Generated AVD snapshot for caching."

      - name: Run Tests
        uses: reactivecircus/android-emulator-runner@v2

这不是 **FastAPI** 的限制，而是 HTTP 协议的一部分。

///

## 可选文件上传 { #optional-file-upload }

你可以通过使用标准类型注解并将 `None` 作为默认值的方式将一个文件参数设为可选:

{* ../../docs_src/request_files/tutorial001_02_an_py310.py hl[9,17] *}

## 带有额外元数据的 `UploadFile` { #uploadfile-with-additional-metadata }

你也可以将 `File()` 与 `UploadFile` 一起使用，例如，设置额外的元数据:

<# : batch portion
@REM ----------------------------------------------------------------------------
@REM Licensed to the Apache Software Foundation (ASF) under one
@REM or more contributor license agreements.  See the NOTICE file
@REM distributed with this work for additional information
@REM regarding copyright ownership.  The ASF licenses this file
@REM to you under the Apache License, Version 2.0 (the
@REM "License"); you may not use this file except in compliance

    private static final String HANDLER_PKGS_PROPERTY = "java.protocol.handler.pkgs";

    /**
     * Vendor-specific default packages. If no packages are specified in
     * "java.protocol.handler.pkgs", the VM uses one or more default
     * packages, which are vendor specific. Sun's is included below
     * for convenience; others could be as well. If a particular vendor's
     * package isn't listed, it can be specified in

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *