public function delete(StockistInterface $stockist)
    {
        /** @var \Limesharp\Stockists\Api\Data\StockistInterface|\Magento\Framework\Model\AbstractModel $stockist */
        $id = $stockist->getId();
        try {
            unset($this->instances[$id]);
            $this->resource->delete($stockist);
        } catch (ValidatorException $e) {
            throw new CouldNotSaveException(__($e->getMessage()));
        } catch (\Exception $e) {
            throw new StateException(
                __('Unable to remove stockist %1', $id)
            );
        }
        unset($this->instances[$id]);
        return true;
    }