老师，您好：
Mac 电脑安装完flutter 后，运行flutter docker会出下面的错误

Could not find a command named "docker".


Run 'flutter -h' (or 'flutter <command> -h') for available flutter commands and options.

使用flutter 检测是已经安装过了

➜  ~ flutter
Manage your Flutter app development.

Common commands:

  flutter create <output directory>
    Create a new Flutter project in the specified directory.

  flutter run [options]
    Run your Flutter application on an attached device or in an emulator.

Usage: flutter <command> [arguments]

Global options:
-h, --help                  Print this usage information.
-v, --verbose               Noisy logging, including all shell commands executed.
                            If used with "--help", shows hidden options. If used with "flutter doctor", shows additional diagnostic information. (Use "-vv" to force verbose logging in those cases.)
-d, --device-id             Target device id or name (prefixes allowed).
    --version               Reports the version of this tool.
    --suppress-analytics    Suppress analytics reporting when this command runs.

Available commands:
  analyze           Analyze the project's Dart code.
  assemble          Assemble and build Flutter resources.
  attach            Attach to a running app.
  bash-completion   Output command line shell completion setup scripts.
  build             Build an executable app or install bundle.
  channel           List or switch Flutter channels.
  clean             Delete the build/ and .dart_tool/ directories.
  config            Configure Flutter settings.
  create            Create a new Flutter project.
  devices           List all connected devices.
  doctor            Show information about the installed tooling.
  downgrade         Downgrade Flutter to the last active version for the current channel.
  drive             Run integration tests for the project on an attached device or emulator.
  emulators         List, launch and create emulators.
  format            Format one or more Dart files.
  gen-l10n          Generate localizations for the current project.
  install           Install a Flutter app on an attached device.
  logs              Show log output for running Flutter apps.
  precache          Populate the Flutter tool's cache of binary artifacts.
  pub               Commands for managing Flutter packages.
  run               Run your Flutter app on an attached device.
  screenshot        Take a screenshot from a connected device.
  symbolize         Symbolize a stack trace from an AOT-compiled Flutter app.
  test              Run Flutter unit tests for the current project.
  upgrade           Upgrade your copy of Flutter.

Run "flutter help <command>" for more information about a command.
Run "flutter help -v" for verbose help output, including less commonly used options.

不知道我是哪里弄错了