public void ThrowIfNullThrowsExceptionWithParameterName()
        {
            TestArgumentItem arg           = null;
            string           parameterName = null;

            try
            {
                arg.ThrowIfNull("param1");
            }
            catch (ArgumentNullException e)
            {
                parameterName = e.ParamName;
            }

            Assert.AreEqual("param1", parameterName);
        }
        public void ThrowIfNullThrowsIfParameterIsNull()
        {
            TestArgumentItem arg = null;

            Assert.Throws <ArgumentNullException>(() => arg.ThrowIfNull("param1"));
        }