code: func SetBootstrapTokensDynamicDefaults(cfg *[]kubeadmapi.BootstrapToken) error {
  	// Populate the .Token field with a random value if unset
  	// We do this at this layer, and not the API defaulting layer
  	// because of possible security concerns, and more practically
  	// because we can't return errors in the API object defaulting
  	// process but here we can.
  	for i, bt := range *cfg {
  		if bt.Token != nil && len(bt.Token.String()) > 0 {
  			continue
  		}
  
  		tokenStr, err := bootstraputil.GenerateBootstrapToken()
  		if err != nil {
  			return errors.Wrap(err, "couldn't generate random token")
  		}
  		token, err := kubeadmapi.NewBootstrapTokenString(tokenStr)
  		if err != nil {
  			return err
  		}
  		(*cfg)[i].Token = token
  	}
  
  	return nil
  }
docs: // SetBootstrapTokensDynamicDefaults checks and sets configuration values for the BootstrapTokens object