/// <summary>
        /// Tries to parse the <c>Coded-URL</c> from a <see cref="StringSource"/>
        /// </summary>
        /// <param name="source">The <see cref="StringSource"/> to parse the <c>Coded-URL</c> from</param>
        /// <param name="codedUrl">The parsed <c>Coded-URL</c></param>
        /// <returns><see langword="true"/> when the <c>Coded-URL</c> could be parsed successfully</returns>
        internal static bool TryParse([NotNull] StringSource source, out Uri codedUrl)
        {
            if (!source.AdvanceIf("<"))
            {
                codedUrl = null;
                return(false);
            }

            // Coded-URL found
            var codedUrlText = source.GetUntil('>');

            if (codedUrlText == null)
            {
                throw new ArgumentException($"{source.Remaining} is not a valid Coded-URL (not ending with '>')", nameof(source));
            }
            source.Advance(1);
            codedUrl = new Uri(codedUrlText, UriKind.RelativeOrAbsolute);
            return(true);
        }
        internal static IEnumerable <EntityTag> Parse(StringSource source)
        {
            while (!source.SkipWhiteSpace())
            {
                bool isWeak;
                if (source.AdvanceIf("W/\"", StringComparison.OrdinalIgnoreCase))
                {
                    isWeak = true;
                }
                else if (!source.AdvanceIf("\""))
                {
                    break;
                }
                else
                {
                    isWeak = false;
                }

                var etagText = source.GetUntil('"');
                if (etagText == null)
                {
                    throw new ArgumentException($"{source.Remaining} is not a valid ETag", nameof(source));
                }

                yield return(new EntityTag(isWeak, etagText));

                if (source.Advance(1).SkipWhiteSpace())
                {
                    break;
                }

                if (!source.AdvanceIf(","))
                {
                    break;
                }
            }
        }