String EncodeHtml(const RichText& text, Index<String>& css,
                  const VectorMap<String, String>& links,
                  const VectorMap<String, String>& labels,
                  const String& path, const String& base = Null, Zoom z = Zoom(8, 40),
                  const VectorMap<String, String>& escape = VectorMap<String, String>(),
                  int imtolerance = 0);
String AsCss(Index<String>& ss);