public async Task <Either <BaseError, Unit> > Handle(
        AddOtherVideoToCollection request,
        CancellationToken cancellationToken)
    {
        await using TvContext dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);

        Validation <BaseError, Parameters> validation = await Validate(dbContext, request);

        return(await LanguageExtensions.Apply(
                   validation,
                   parameters => ApplyAddOtherVideoRequest(dbContext, parameters)));
    }
 private static async Task <Validation <BaseError, Parameters> > Validate(
     TvContext dbContext,
     AddOtherVideoToCollection request) =>
 (await CollectionMustExist(dbContext, request), await ValidateOtherVideo(dbContext, request))