in content/resources/js/prettify.js [1177:1186]
function registerLangHandler(handler, fileExtensions) {
for (var i = fileExtensions.length; --i >= 0;) {
var ext = fileExtensions[i];
if (!langHandlerRegistry.hasOwnProperty(ext)) {
langHandlerRegistry[ext] = handler;
} else if (window['console']) {
console['warn']('cannot override language handler %s', ext);
}
}
}