/// <summary>
/// Add or remove listing from favorites command handler async.
/// </summary>
/// <param name="listingCommand">Add or remove listing from favorites command.</param>
public async Task HandleAddOrRemoveListingFromFavoritesCommandAsync(AddOrRemoveListingFromFavoritesCommand listingCommand)
{
await listingRepository.AddOrRemoveListingFromFavoritesAsync(listingCommand.UserId, listingCommand.ListingId, listingCommand.IsFavorite);
}