quota/quota.go
func (s *QuotaService) Set(appName string, inUse int) error {
	q, err := s.Storage.Get(appName)
	if err != nil {
		return err
	}
	if inUse < 0 {
		return quota.ErrLessThanZero
	}
	if !q.IsUnlimited() && inUse > q.Limit {
		return &quota.QuotaExceededError{
			Requested: uint(inUse),
			Available: uint(q.Limit),
		}
	}
	return s.Storage.Set(appName, inUse)
}
func (s *QuotaService) Set(appName string, inUse int) error {
	q, err := s.Storage.Get(appName)
	if err != nil {
		return err
	}
	if inUse < 0 {
		return quota.ErrLessThanZero
	}
	if !q.IsUnlimited() && inUse > q.Limit {
		return &quota.QuotaExceededError{
			Requested: uint(inUse),
			Available: uint(q.Limit),
		}
	}
	return s.Storage.Set(appName, inUse)
}
// Set redefines the inuse units of the app. This new value must be smaller
// than or equal to the current limit of the app. It also must be a non negative number.
// Set implements Set method from QuotaService interface