src/vs/workbench/contrib/comments/browser/commentThreadHeader.ts/CommentThreadHeader/_fillHead
class CommentThreadHeader:	protected _fillHead(): void {
		const titleElement = dom.append(this._headElement, dom.$('.review-title'));

		this._headingLabel = dom.append(titleElement, dom.$('span.filename'));
		this.createThreadLabel();

		const actionsContainer = dom.append(this._headElement, dom.$('.review-actions'));
		this._actionbarWidget = new ActionBar(actionsContainer, {
			actionViewItemProvider: createActionViewItem.bind(undefined, this.instantiationService)
		});

		this._register(this._actionbarWidget);

		this._collapseAction = new Action('review.expand', nls.localize('label.collapse', "Collapse"), COLLAPSE_ACTION_CLASS, true, () => this._delegate.collapse());

		const menu = this._commentMenus.getCommentThreadTitleActions(this._contextKeyService);
		this.setActionBarActions(menu);

		this._register(menu);
		this._register(menu.onDidChange(e => {
			this.setActionBarActions(menu);
		}));

		this._register(dom.addDisposableListener(this._headElement, dom.EventType.CONTEXT_MENU, e => {
			return this.onContextMenu(e);
		}));

		this._actionbarWidget.context = this._commentThread;
	}