code: function(eventName, options) {
          var allCallbacks = lib$rsvp$events$$callbacksFor(this), callbacks, callback;
  
          if (callbacks = allCallbacks[eventName]) {
            // Don't cache the callbacks.length since it may grow
            for (var i=0; i<callbacks.length; i++) {
              callback = callbacks[i];
  
              callback(options);
            }
          }
        }
docs: Use `trigger` to fire custom events. For example:
  
  ```javascript
  object.on('foo', function(){
  console.log('foo event happened!');
  });
  object.trigger('foo');
  'foo event happened!' logged to the console
  ```
  
  You can also pass a value as a second argument to `trigger` that will be
  passed as an argument to all event listeners for the event:
  
  ```javascript
  object.on('foo', function(value){
  console.log(value.name);
  });
  
  object.trigger('foo', { name: 'bar' });
  'bar' logged to the console
  ```
  
  @method trigger
  @for RSVP.EventTarget
  @private
  @param {String} eventName name of the event to be triggered
  @param {Any} options optional value to be passed to any event handlers for
  the given `eventName`