code: function eventListenerHub(emitter, eventName) {
    var self = object.create(eventListenerHub.prototype);
  
    self.emitter = emitter;
    self.eventName = eventName;
    self.handlers = [];
    self.defaultHandlerFn = null;
  
    return self;
  }
docs: A hub keeps track of an event and its listeners on a particular context and
  is able to manage them on that context
  
  @param {EventEmitter} emitter
  @param {string} eventName