src/vs/workbench/contrib/comments/common/commentModel.ts/CommentsModel/groupByResource
class CommentsModel:	private groupByResource(owner: string, commentThreads: CommentThread[]): ResourceWithCommentThreads[] {
		const resourceCommentThreads: ResourceWithCommentThreads[] = [];
		const commentThreadsByResource = new Map<string, ResourceWithCommentThreads>();
		for (const group of groupBy(commentThreads, CommentsModel._compareURIs)) {
			commentThreadsByResource.set(group[0].resource!, new ResourceWithCommentThreads(owner, URI.parse(group[0].resource!), group));
		}

		commentThreadsByResource.forEach((v, i, m) => {
			resourceCommentThreads.push(v);
		});

		return resourceCommentThreads;
	}