public async Task UpdateAsync()
        {
            IList <Source> sources = null;

            _errors.Log($"{nameof(ArticlesClient)}.{nameof(UpdateAsync)}()", () =>
            {
                sources = _sources.GetActive();
            });

            foreach (var source in sources)
            {
                IList <RssItem> items = await GetItems(source);

                IEnumerable <Article> articles = GetArticles(items, source);

                SaveArticles(articles, source);
                UpdateDate(source);
            }
        }