public void ShouldParseNegativeDoubleSucceed(
            string jsonFragment,
            double expectedValue
            )
        {
            IJsonElement parser = new JsonNumber();
            string       jsonRemainder;

            Assert.IsTrue(
                parser.Parse(
                    jsonFragment,
                    out jsonRemainder
                    )
                );
            Assert.AreEqual(
                expectedValue,
                parser.AsDouble()
                );
        }