public async Task <string> Handle(CreateCityCommand request, CancellationToken cancellationToken)
{
var cityExist = await _customerRepository.CityExistAsync(request.Name);
if (cityExist)
{
throw new CityAlreadyExistException(request.Name);
}
var city = new City(request.CityId, request.Name);
_customerRepository.AddCity(city);
await _customerRepository.UnitOfWork.SaveEntitiesAsync();
return(city.Id.ToString());
}