public double CalculatePercentChanged()
{
string page1 = _cache;
string page2 = Helpers.WebHelper.DownloadWebPage(_url);
if (page2 == "")
{
Error();
return -1.0;
}
diff_match_patch difflib = new diff_match_patch();
List<Diff> list = difflib.diff_main(page1, page2);
double levenshtein = difflib.diff_levenshtein(list);
double length = (page1.Length > page2.Length) ? page1.Length : page2.Length;
double percentDifferent = levenshtein / length * 100;
return percentDifferent;
}