public CovidDataUpdater(
     ILogger <CovidDataUpdater> logger
     , ApplicationDbContext context
     , IDataSetRetriever retriever)
 {
     _logger    = logger;
     _context   = context;
     _retriever = retriever;
 }
 public DataSetFileReader(IDataSetRetriever dataSetRetriever)
 {
     _dataSetRetriever = dataSetRetriever;
 }