code: function() {
  			var self = this;
  			if (!this.collabFileAnnotationsUpdateTimeoutId) {
  				// No delayed update is assigned. Assign one.
  				// This is necessary because we don't want duplicate UI action within a short period.
  				this.collabFileAnnotationsUpdateTimeoutId = setTimeout(function() {
  					self.collabFileAnnotationsUpdateTimeoutId = 0;
  					var annotations = [];
  					var editingFileUsers = {}; // map from location to list of usernames indicating all users that are typing on this file
  					for (var key in self.collabFileAnnotations) {
  						if (self.collabFileAnnotations.hasOwnProperty(key)) {
  							var annotation = self.collabFileAnnotations[key];
  							annotations.push(annotation);
  							if (annotation.editing) {
  								if (!editingFileUsers[annotation.location]) {
  									editingFileUsers[annotation.location] = [];
  								}
  								editingFileUsers[annotation.location].push(annotation.name);
  							}
  						}
  					}
  					// Add editing annotations
  					for (var location in editingFileUsers) {
  						if (editingFileUsers.hasOwnProperty(location)) {
  							annotations.push(new CollabFileEditingAnnotation(location, editingFileUsers[location]));
  						}
  					}
  					self.fileClient.dispatchEvent({
  						type: 'AnnotationChanged',
  						removeTypes: [CollabFileAnnotation],
  						annotations: annotations
  					});
  				}, COLLABORATOR_ANNOTATION_UPDATE_DELAY);
  			}
  		}
docs: Request a file annotation UI update