src/vs/platform/actions/browser/dropdownWithPrimaryActionViewItem.ts/DropdownWithPrimaryActionViewItem/constructor
class DropdownWithPrimaryActionViewItem:	constructor(
		primaryAction: MenuItemAction,
		dropdownAction: IAction,
		dropdownMenuActions: IAction[],
		className: string,
		private readonly _contextMenuProvider: IContextMenuProvider,
		@IKeybindingService _keybindingService: IKeybindingService,
		@INotificationService _notificationService: INotificationService
	) {
		super(null, primaryAction);
		this._primaryAction = new MenuEntryActionViewItem(primaryAction, _keybindingService, _notificationService);
		this._dropdown = new DropdownMenuActionViewItem(dropdownAction, dropdownMenuActions, this._contextMenuProvider, {
			menuAsChild: true,
			classNames: ['codicon', 'codicon-chevron-down']
		});
	}