What is UnsolicitedPackages {S_Actor, Sphere...}

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#1

After cooked, I found a lot of Engine Content I don’t know where they comes from.Such as
/Engine/EditorResources/S_Actor
/Engine/EngineMeshes/Sphere

262995-uunknownenginecontent.png

Skip Engine Content was Checked.

And I found they are added in CookOnTheFlyServer.cpp line 5857~5868 in UE4.21

262996-unsolicitedpackage.png
262996-unsolicitedpackage.png1702×450 313 KB

Anyone knows about these assets and should I pakcage these assets into my publish game?

Thanks!