function EventEmitter() {
      this.evets = [];
}

EventEmitter.prototype.on = function(event, callback) {
      this.events[event] = callback();
      var args = arguments;

      callback(args);
}

EventEmitter.prototype.emit = function(event, arguments) {
      this.events[event].apply(this);
}

const eventEmitter = new EventEmitter();

eventEmitter.on('my-event', function() {
      console.log(arguments);
      //'some data', null, 'some data again'
});

eventEmitter.emit('my-event', 'some-data', null, 'some data again');