code: func NewSystemCommand(dockerCli command.Cli) *cobra.Command {
  	cmd := &cobra.Command{
  		Use:   "system",
  		Short: "Manage Docker",
  		Args:  cli.NoArgs,
  		RunE:  command.ShowHelp(dockerCli.Err()),
  	}
  	cmd.AddCommand(
  		NewEventsCommand(dockerCli),
  		NewInfoCommand(dockerCli),
  		newDiskUsageCommand(dockerCli),
  		newPruneCommand(dockerCli),
  		newDialStdioCommand(dockerCli),
  	)
  
  	return cmd
  }
docs: // NewSystemCommand returns a cobra command for `system` subcommands