public function getForeignKeyValuePair($related)
    {
        $foreignKey = $this->getForeignKey();

        if ($related) {
            $wrapper = $this->factory->make($related);

            $relatedKey = $this->relatedMap->getKeyName();

            return [
                $foreignKey      => $wrapper->getEntityAttribute($relatedKey),
                $this->morphType => $wrapper->getMap()->getMorphClass(),
            ];
        } else {
            return [$foreignKey => null];
        }
    }