public DayCalculatorTests()
        {
            var services = new ServiceCollection();

            services.AddOptions();
            services.AddLogging(configure => configure.AddNLog());
            NLog.LogManager.LoadConfiguration("nlog.config");

            services.Boot();

            var serviceProvider = services.BuildServiceProvider();
            var loggerFactory   = serviceProvider.GetRequiredService <ILoggerFactory>();

            _logger        = loggerFactory.CreateLogger <DayCalculatorTests>();
            _dayCalculator = serviceProvider.GetService <IDayCalculator>();
        }
 public DayCalculatorTests()
 {
     _dayCalculator = new DayCalculator();
 }