/// <summary>
/// Removes the supplied share from the watchlist.
/// </summary>
/// <param name="userId">The unique identifier of the user who owns the watchlist.</param>
/// <param name="watchlistId">The unique identifier of the watchlist.</param>
/// <param name="symbol">The share symbol.</param>
private Watchlist GetWatchlist(Guid userId, Guid watchlistId)
{
Watchlist watchlist = _watchlistRepository.GetById(watchlistId);
if (watchlist == null || watchlist.UserId != userId)
{
throw new EntityNotFoundException(nameof(Watchlist), watchlistId);
}
return(watchlist);
}