src/vs/workbench/contrib/comments/browser/commentThreadWidget.ts/ReviewZoneWidget/createReplyButton
class ReviewZoneWidget:	private createReplyButton(commentEditor: ICodeEditor, commentForm: HTMLElement) {
		this._reviewThreadReplyButton = <HTMLButtonElement>dom.append(commentForm, dom.$(`button.review-thread-reply-button.${MOUSE_CURSOR_TEXT_CSS_CLASS_NAME}`));
		this._reviewThreadReplyButton.title = this._commentOptions?.prompt || nls.localize('reply', "Reply...");

		this._reviewThreadReplyButton.textContent = this._commentOptions?.prompt || nls.localize('reply', "Reply...");
		// bind click/escape actions for reviewThreadReplyButton and textArea
		this._disposables.add(dom.addDisposableListener(this._reviewThreadReplyButton, 'click', _ => this.expandReplyArea()));
		this._disposables.add(dom.addDisposableListener(this._reviewThreadReplyButton, 'focus', _ => this.expandReplyArea()));

		commentEditor.onDidBlurEditorWidget(() => {
			if (commentEditor.getModel()!.getValueLength() === 0 && commentForm.classList.contains('expand')) {
				commentForm.classList.remove('expand');
			}
		});
	}