code: function() {
  			if (!this._treeModel.getAnnotations) {
  				return;
  			}
  
  			if (this._annotationRefreshRequested) {
  				return;
  			}
  
  			// Refresh annotation in next tick to avoid duplicate requests
  			var tree = this;
  			this._annotationRefreshRequested = true;
  			setTimeout(function() {
  				tree._annotationRefreshRequested = false;
  				tree._redrawAnnotation();
  			}, 0);
  		}
docs: Request an annotation refresh using the information provided by
  model.getAnnotations().