[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, Category="PCG|Metadata") void MergeAttributesByKey ( int64 KeyA, const [UPCGMetadata](API\Plugins\PCG\Metadata\UPCGMetadata) * MetadataA, int64 KeyB, const [UPCGMetadata](API\Plugins\PCG\Metadata\UPCGMetadata) * MetadataB, int64 TargetKey, [EPCGMetadataOp](API\Plugins\PCG\Metadata\EPCGMetadataOp) Op, int64 & OutKey )