code: func newTrustKeyCommand(dockerCli command.Streams) *cobra.Command {
  	cmd := &cobra.Command{
  		Use:   "key",
  		Short: "Manage keys for signing Docker images",
  		Args:  cli.NoArgs,
  		RunE:  command.ShowHelp(dockerCli.Err()),
  	}
  	cmd.AddCommand(
  		newKeyGenerateCommand(dockerCli),
  		newKeyLoadCommand(dockerCli),
  	)
  	return cmd
  }
docs: // newTrustKeyCommand returns a cobra command for `trust key` subcommands