private static void CheckNameValueFormat(StringSegment name, StringSegment value)
 {
     HeaderUtilities.CheckValidToken(name, nameof(name));
     CheckValueFormat(value);
 }
        public StringWithQualityHeaderValue(StringSegment value)
        {
            HeaderUtilities.CheckValidToken(value, nameof(value));

            _value = value;
        }
 private static void CheckIsValidToken(StringSegment item)
 {
     HeaderUtilities.CheckValidToken(item, nameof(item));
 }