in src/legacy/select.ts [43:53]
let returnValue: any = function() {
let state = createCursorFromSelector<T>(selector, arguments);
let args = Array.prototype.slice.call(arguments);
if (typeof args[argumentPosition] === typeof undefined) {
for (var i = args.length; i < argumentPosition; i++) {
args[i] = undefined;
}
args[argumentPosition] = state;
}
return target.apply(context, args);
};