public async Task<PromoContract> Create(PromoContract promoContract)
{
if (promoContract == null)
{
throw new ArgumentNullException(nameof(promoContract));
}
await _promoContractValidator.ValidateAsync(promoContract, options => options.IncludeRuleSets("Create").ThrowOnFailures());
_logger.LogDebug("Promo successfully validated.");