src/vs/workbench/contrib/comments/browser/commentsEditorContribution.ts/CommentController/beginComputeCommentingRanges
class CommentController:	private beginComputeCommentingRanges() {
		if (this._computeCommentingRangeScheduler) {
			if (this._computeCommentingRangePromise) {
				this._computeCommentingRangePromise.cancel();
				this._computeCommentingRangePromise = null;
			}

			this._computeCommentingRangeScheduler.trigger(() => {
				const editorURI = this.editor && this.editor.hasModel() && this.editor.getModel().uri;

				if (editorURI) {
					return this.commentService.getComments(editorURI);
				}

				return Promise.resolve([]);
			}).then(commentInfos => {
				const meaningfulCommentInfos = coalesce(commentInfos);
				this._commentingRangeDecorator.update(this.editor, meaningfulCommentInfos);
			}, (err) => {
				onUnexpectedError(err);
				return null;
			});
		}
	}