src/vs/workbench/contrib/search/browser/searchWidget.ts/SearchWidget/renderToggleReplaceButton
class SearchWidget:	private renderToggleReplaceButton(parent: HTMLElement): void {
		const opts: IButtonOptions = {
			buttonBackground: undefined,
			buttonBorder: undefined,
			buttonForeground: undefined,
			buttonHoverBackground: undefined,
			buttonSecondaryBackground: undefined,
			buttonSecondaryForeground: undefined,
			buttonSecondaryHoverBackground: undefined,
			buttonSeparator: undefined
		};
		this.toggleReplaceButton = this._register(new Button(parent, opts));
		this.toggleReplaceButton.element.setAttribute('aria-expanded', 'false');
		this.toggleReplaceButton.element.classList.add('toggle-replace-button');
		this.toggleReplaceButton.icon = searchHideReplaceIcon;
		// TODO@joao need to dispose this listener eventually
		this.toggleReplaceButton.onDidClick(() => this.onToggleReplaceButton());
		this.toggleReplaceButton.element.title = nls.localize('search.replace.toggle.button.title', "Toggle Replace");
	}