public function delete()
    {
        $this->exitIfModelNotSet();

        $params = [
            'id'    => $this->model->getKey(),
            'type'  => $this->model->getDocumentType(),
            'index' => $this->model->getDocumentIndex(),
        ];

        // check if the document exists before deleting
        if ($this->connection->existsStatement($params)) {
            return $this->connection->deleteStatement($params);
        }

        return true;
    }