code: func NewCommandStartAggregator(defaults *AggregatorOptions, stopCh <-chan struct{}) *cobra.Command {
  	o := *defaults
  	cmd := &cobra.Command{
  		Short: "Launch a API aggregator and proxy server",
  		Long:  "Launch a API aggregator and proxy server",
  		RunE: func(c *cobra.Command, args []string) error {
  			if err := o.Complete(); err != nil {
  				return err
  			}
  			if err := o.Validate(args); err != nil {
  				return err
  			}
  			if err := o.RunAggregator(stopCh); err != nil {
  				return err
  			}
  			return nil
  		},
  	}
  
  	o.AddFlags(cmd.Flags())
  	return cmd
  }
docs: // NewCommandStartAggregator provides a CLI handler for 'start master' command
  // with a default AggregatorOptions.