private static void CheckInvalidGetStringWithQualityLength(string input, int startIndex)
        {
            object result = null;

            Assert.Equal(0, StringWithQualityHeaderValue.GetStringWithQualityLength(input, startIndex, out result));
            Assert.Null(result);
        }
        private static void CallGetStringWithQualityLength(string input, int startIndex, int expectedLength,
                                                           out StringWithQualityHeaderValue result)
        {
            object temp = null;

            Assert.Equal(expectedLength, StringWithQualityHeaderValue.GetStringWithQualityLength(input,
                                                                                                 startIndex, out temp));
            result = temp as StringWithQualityHeaderValue;
        }