code: func newDependencyUpdateCmd(out io.Writer) *cobra.Command {
  	duc := &dependencyUpdateCmd{out: out}
  
  	cmd := &cobra.Command{
  		Use:     "update [flags] CHART",
  		Aliases: []string{"up"},
  		Short:   "update charts/ based on the contents of requirements.yaml",
  		Long:    dependencyUpDesc,
  		RunE: func(cmd *cobra.Command, args []string) error {
  			cp := "."
  			if len(args) > 0 {
  				cp = args[0]
  			}
  
  			var err error
  			duc.chartpath, err = filepath.Abs(cp)
  			if err != nil {
  				return err
  			}
  
  			duc.helmhome = settings.Home
  
  			return duc.run()
  		},
  	}
  
  	f := cmd.Flags()
  	f.BoolVar(&duc.verify, "verify", false, "verify the packages against signatures")
  	f.StringVar(&duc.keyring, "keyring", defaultKeyring(), "keyring containing public keys")
  	f.BoolVar(&duc.skipRefresh, "skip-refresh", false, "do not refresh the local repository cache")
  
  	return cmd
  }
docs: // newDependencyUpdateCmd creates a new dependency update command.