public void ConvertTest()
        {
            var converter = new StringLengthToVisibilityConverter();

            var actual = converter.Convert(string.Empty, null, null, CultureInfo.InvariantCulture);

            Assert.AreEqual(Visibility.Collapsed, actual);

            actual = converter.Convert("test", null, null, CultureInfo.InvariantCulture);

            Assert.AreEqual(Visibility.Visible, actual);

            actual = converter.Convert(null, null, null, CultureInfo.InvariantCulture);
            
            Assert.AreEqual(Visibility.Collapsed, actual);
        }
        public void ConvertBackTest()
        {
            var converter = new StringLengthToVisibilityConverter();

            converter.ConvertBack(null, null, null, CultureInfo.InvariantCulture);
        }