public void IsNumberTest()
 {
     Assert.AreEqual(_presentationModel.IsNumber('0'), true);
     Assert.AreEqual(_presentationModel.IsNumber('9'), true);
     Assert.AreEqual(_presentationModel.IsNumber('a'), false);
     Assert.AreEqual(_presentationModel.IsNumber('@'), false);
     Assert.AreEqual(_presentationModel.IsNumber('\b'), true);
 }