public function getEditForm($id = null, $fields = null)
    {
        $form = parent::getEditForm($id, $fields);
        if ($this->modelClass == Order::class) {
            /** @var GridFieldConfig $config */
            $config = $form
                ->Fields()
                ->fieldByName($this->sanitiseClassName($this->modelClass))
                ->getConfig();

            $config
                ->getComponentByType(GridFieldSortableHeader::class)
                ->setFieldSorting([ 'StatusI18N' => 'Status' ]);

            $config
                ->getComponentByType(GridFieldDetailForm::class)
                ->setItemRequestClass(OrderGridFieldDetailForm_ItemRequest::class); //see below
        }

        if ($this->modelClass == OrderStatusLog::class) {
            /** @var GridFieldConfig $config */
            $config = $form
                ->Fields()
                ->fieldByName($this->sanitiseClassName($this->modelClass))
                ->getConfig();

            // Remove add new button
            $config->removeComponentsByType($config->getComponentByType(GridFieldAddNewButton::class));
        }

        return $form;
    }