src/vs/workbench/api/common/extHostComments.ts/ExtHostCommentsImpl/$toggleReaction
class ExtHostCommentsImpl:		$toggleReaction(commentControllerHandle: number, threadHandle: number, uri: UriComponents, comment: languages.Comment, reaction: languages.CommentReaction): Promise<void> {
			const commentController = this._commentControllers.get(commentControllerHandle);

			if (!commentController || !commentController.reactionHandler) {
				return Promise.resolve(undefined);
			}

			return asPromise(() => {
				const commentThread = commentController.getCommentThread(threadHandle);
				if (commentThread) {
					const vscodeComment = commentThread.getCommentByUniqueId(comment.uniqueIdInThread);

					if (commentController !== undefined && vscodeComment) {
						if (commentController.reactionHandler) {
							return commentController.reactionHandler(vscodeComment, convertFromReaction(reaction));
						}
					}
				}

				return Promise.resolve(undefined);
			});
		}