public void DeleteReaderTest()
        {
            AddReaderTest();
            Assert.AreEqual(1, _dataLayer.GetAllReaders().Count());
            Reader reader = _dataLayer.GetAllReaders().First();

            _dataLayer.DeleteReader(reader);
            Assert.AreEqual(0, _dataLayer.GetAllReaders().Count());
            Assert.IsNull(_dataLayer.GetReader(reader.Id));
        }