javascript invoke callback

invoke_callback.js

var __callback = function (cb) {
  if (typeof cb == 'function') {
    delete arguments['0'];
    var args = [];
    for (var key in arguments) {
      if (arguments.hasOwnProperty(key)) {
        args.push(arguments[key]);
      }
    }
    cb.apply(null, args);
  }
};