public function getRequiredRelationProperties(): array
    {
        if (null !== $this->requiredRelationProperties) {
            return $this->requiredRelationProperties;
        }
        $traits = $this->reflectionClass->getTraits();
        $return = [];
        foreach ($traits as $traitName => $traitReflection) {
            if (false === \ts\stringContains($traitName, '\\HasRequired')) {
                continue;
            }
            if (false === \ts\stringContains($traitName, '\\Entity\\Relations\\')) {
                continue;
            }

            $property          = $traitReflection->getProperties()[0]->getName();
            $return[$property] = $this->getTypesFromVarComment(
                $property,
                $this->getReflectionHelper()->getTraitProvidingProperty($traitReflection, $property)
            );
        }
        $this->requiredRelationProperties = $return;

        return $return;
    }