in Readability.js [460:473]
function toAbsoluteURI(uri) {
// Leave hash links alone if the base URI matches the document URI:
if (baseURI == documentURI && uri.charAt(0) == "#") {
return uri;
}
// Otherwise, resolve against base URI:
try {
return new URL(uri, baseURI).href;
} catch (ex) {
// Something went wrong, just return the original:
}
return uri;
}