protected function initSidenav($sidenavId)
    {
        $this->sidenavToggleButtonOptions = ArrayHelper::merge([
            'label' => false,
            'icon' => [
                'name' => 'menu'
            ],
            'type' => Button::TYPE_FLAT,
        ], $this->sidenavToggleButtonOptions);

        if (!isset($this->sidenavToggleButtonOptions['options']['data-target'])) {
            $this->sidenavToggleButtonOptions['options']['data-target'] = $sidenavId;
        }

        Html::addCssClass($this->sidenavToggleButtonOptions['options'], ['trigger' => 'sidenav-trigger']);
    }