public static void Main()
    {
        TestToString test = new TestToString();

        test.CallToString1();
        Console.WriteLine();
        test.CallToString2();
        Console.WriteLine();
        test.CallToString3();
    }
        public void TestString()
        {
            var          converter      = _converterBuilder.BuildConverter(typeof(string));
            const string expectedValue  = "thisIsATest";
            var          valueToConvert = new TestToString(expectedValue);
            object       convertedValue = converter(valueToConvert);

            Assert.IsInstanceOf <string>(convertedValue);
            Assert.AreEqual(expectedValue, convertedValue);
            Assert.IsNull(converter(null));
        }