private void RewriteStyleAttributes(ResponseAnalysisContext context, string html)
        {
            var headIndex = html.IndexOf("</head>", StringComparison.OrdinalIgnoreCase);

            if (headIndex == -1)
            {
                return;
            }

            SortedList <string, StringSegment> inlineStyles = null;

            foreach (var index in FastHtmlParser.FindAllAttributeIndexes(html, "style"))
            {
                // get content
                var inner = FastHtmlParser.GetAttributeValueAtName(html, "style", index);
                if (inner.Length == 0)
                {
                    continue;
                }

                if (inlineStyles == null)
                {
                    inlineStyles = new SortedList <string, StringSegment>();
                }

                // compute hash
                var hash = ComputeHash(inner.Trim());

                if (!inlineStyles.ContainsKey(hash))
                {
                    inlineStyles.Add(hash, inner);
                }

                // add change
                context.AddChange(TextChange.Remove(html, index, inner.Offset + inner.Length + 1 - index));

                var tagIndex       = FastHtmlParser.FindOpenTagAtAttribute(html, index);
                var classAttribute = FastHtmlParser.GetAttributeValueAtTag(html, "class", tagIndex);
                if (classAttribute.Length > 0)
                {
                    context.AddChange(TextChange.Insert(html, classAttribute.Offset + classAttribute.Length, "_" + hash));
                }
                else
                {
                    context.AddChange(FastHtmlParser.CreateInsertAttributeChange(html, tagIndex, "class", "_" + hash));
                }
            }

            // assemble inline styles
            if (inlineStyles != null && inlineStyles.Count > 0)
            {
                var hashBuilder = new InplaceStringBuilder(inlineStyles.Count * HashBytes * 2);
                foreach (var entry in inlineStyles)
                {
                    hashBuilder.Append(entry.Key);
                }

                var hash = ComputeHash(hashBuilder.ToString());
                if (!InlineContentService.ContainsStyleByHash(hash))
                {
                    var contentBuilder = StringBuilderPool.Get();
                    foreach (var entry in inlineStyles)
                    {
                        contentBuilder.Append('.');
                        contentBuilder.Append('_');
                        contentBuilder.Append(entry.Key);
                        contentBuilder.Append('{');
                        contentBuilder.Append(entry.Value.Value);
                        contentBuilder.Append('}');
                    }
                    InlineContentService.TryAddStyleByHash(hash, contentBuilder.ToString());
                    StringBuilderPool.Return(contentBuilder);
                }

                var tag = $"<link rel=\"stylesheet\" href=\"/.waf/styles/{hash}\" type=\"text/css\" />";
                context.AddChange(TextChange.Insert(html, headIndex, tag));
            }
        }