This library connects to a given url and tries to find references to icons that represent the page. Multiple standards are used for this:
- default favicon.ico in root and as "link rel" wikipedia.org/wiki/Favicon
- apple touch icon Apple docs
- Open graph image ogp.me
- Windows 8 tile images Microsoft technet
All images are converted to absolute urls and checked if connecting to them works. It does a GET request, but closes the connection after the http header.