docs: func (s *PurchaseOfferingInput) Validate() error {
  	invalidParams := request.ErrInvalidParams{Context: "PurchaseOfferingInput"}
  	if s.OfferingId != nil && len(*s.OfferingId) < 32 {
  		invalidParams.Add(request.NewErrParamMinLen("OfferingId", 32))
  	}
  	if s.OfferingPromotionId != nil && len(*s.OfferingPromotionId) < 4 {
  		invalidParams.Add(request.NewErrParamMinLen("OfferingPromotionId", 4))
  	}
  
  	if invalidParams.Len() > 0 {
  		return invalidParams
  	}
  	return nil
  }