public async Task <IList <Tweet> > FetchAndUpdateLast100Tweets(CancellationToken ct = default)
{
// Create tasks.
var dbTweetsTask = _tweetDbRepository.GetLast100ToritoTweets(ct);
var clientTweetsTask = _tweetClientRepository.GetLast100ToritoTweets(ct);
// Results.
var dbtweetsResult = await dbTweetsTask;
var dboTweets = _mapper.Map <IList <Tweet> >(dbtweetsResult);
var clientTweetsResult = await clientTweetsTask;
// Compare client results with Dbo.
var toAddDbTweets = clientTweetsResult.Except(dboTweets, new TweetEqualityComparerById()).ToList();
// Add not added tweets to DB.
var toAddDbTweetsDbo = _mapper.Map <IList <TweetDbo> >(toAddDbTweets);
await _tweetDbRepository.AddList(toAddDbTweetsDbo);
return(clientTweetsResult);
}