public async Task <Advertisement> CreateAdvertisementAsync(Advertisement advertisement)
{
if (advertisement == null)
{
throw new ArgumentNullException(nameof(advertisement));
}
_dbContext.Advertisements.Add(advertisement);
await _dbContext.SaveChangesAsync();
return(advertisement);
}
public async Task <Phone> CreatePhoneAsync(Phone phone)
{
if (phone == null)
{
throw new ArgumentNullException(nameof(phone));
}
_dbContext.Phones.Add(phone);
await _dbContext.SaveChangesAsync();
return(phone);
}