in src/common/builder.js [32:45]
function clobber (obj, key, value) {
var needsProperty = false;
try {
obj[key] = value;
} catch (e) {
needsProperty = true;
}
// Getters can only be overridden by getters.
if (needsProperty || obj[key] !== value) {
utils.defineGetter(obj, key, function () {
return value;
});
}
}