code: function(eventType, attributeKey, attributeValue) {
      var attrsKey = this._event_attributes_key(eventType);
      for(var i = 0; i < this._events.length ; i++) {
        var evt = this._events[i];
        if ( (evt.eventType === eventType) && (evt[attrsKey][attributeKey] === attributeValue) ) {
          return evt;
        }
      }
      return null;
    }
docs: Return the Event for the given type that has the given attribute value
  @param {String} eventType
  @param {String} attributeKey
  @param {String} attributeValue
  @returns {Object} evt - The event if found, null otherwise