public function setParent(ModelInterface $childModel, ModelInterface $parentModel)
    {
        $condition = $this->relationships->getChildCondition(
            $parentModel->getProviderName(),
            $childModel->getProviderName()
        );
        if (!$condition instanceof ParentChildConditionInterface) {
            throw new DcGeneralRuntimeException(
                'No condition defined from ' . $parentModel->getProviderName() . ' to ' . $childModel->getProviderName()
            );
        }

        $condition->applyTo($parentModel, $childModel);
    }