public function deleteMany($ids = null)
    {
        if (is_null($ids)) {
            $parameters = [
                'performAll' => true
            ];
        } else {
            $parameters = [
                'ids' => implode(',', (array) $ids),
            ];
        }

        $response = $this->ontraport->delete(
            $this->getNamespace(), $this->toArray($parameters)
        );

        // When deleting many objects, we get a string for the data field in the response,
        // saying "Deleted". When an object does not exist, it is ignored by oap. I believe
        // its safe to assume that we can always return successfuly here. Unless we receive
        // a non 200 status code in which case an InvalidRequest would be thrown.

        return true;
    }