code: func LocalTagHandler(ctx *tagContext) error {
  	if len(ctx.params) == 0 {
  		ctx.col.TimeZone = time.Local
  	} else {
  		var err error
  		ctx.col.TimeZone, err = time.LoadLocation(ctx.params[0])
  		if err != nil {
  			return err
  		}
  	}
  	return nil
  }
docs: // LocalTagHandler describes local tag handler