public async Task <GetProductResponse> GetProductByIdAsync(int productId, string email)
{
Product product = await _dataContext.Products
.AsNoTracking()
.SingleOrDefaultAsync(p => p.ProductId == productId);
GetProductResponse response = _mapper.Map <GetProductResponse>(product);
response.IsFavourite = await _favouriteService.IsProductFavourite(email, productId);
return(response);
}