void GetSubsystemRequirementBits ( [FMassExternalSubsystemBitSet](API\Plugins\MassEntity\FMassExternalSubsystemBitSet) & OutConstSubsystemsBitSet, [FMassExternalSubsystemBitSet](API\Plugins\MassEntity\FMassExternalSubsystemBitSet) & OutMutableSubsystemsBitSet )