public async Task AddQuotationItemAsync(Guid quotationId, Guid itemId, Guid priceListId, Guid?taxId, int units = 1)
{
Guard.AgainstNull(quotationId, nameof(quotationId));
Guard.AgainstNull(priceListId, nameof(priceListId));
Guard.AgainstNull(itemId, nameof(itemId));
Quotation quotation = await _quotationRepository.GetByIdAsync(quotationId);
Item item = await _itemRepository.GetByIdAsync(itemId);
ItemQuoted itemQuoted = new(item.Id, item.Name, item.Description);
PriceList priceList = await _priceListRepository.GetByIdAsync(priceListId);
QuotationItem quotationItem = new(itemQuoted, priceList.UnitPrice, units, taxId);
quotation.AddItem(quotationItem);
await _quotationRepository.UpdateAsync(quotation);
}