public async Task <IEnumerable <VendorResponse> > GetByEventId(Guid id)
        {
            var vendors = await _vendorRepository.GetByEventId(id);

            var allVendors = await _vendorRepository.GetAsync();

            var result = allVendors.Where(v => vendors.All(x => x.Id != v.Id));

            /*var result = await _vendorRepository.GetByEventId(id);*/
            return(result.Select(x => _vendorMapper.Map(x)));
        }