code: function(type,eventInitDict){
  		this.type = type;
  		var session = eventInitDict && (eventInitDict.session || null);
  		Object.defineProperty(this, 'session', {
  			get: function () {
  				return session;
  			}
  		});
  	}
docs: /*
  PresentEvent: for details please refer to http://www.w3.org/2014/secondscreen/presentation-api/20140721/#presentevent