Should Dalvik Cache be wiped in Android OS that supports ART? When switching custom ROMs (in ART), is it necessary to wipe the Dalvik Cache?

Wiping the Cache is necessary, but should wiping Dalvik (which doesn't exist in Android Lollipop and afterward) be necessary?

What impact will it cause if we wipe Dalvik (something not present)?

In ART, what does the Dalvik cache contains? (is it an empty folder?)
No, you don't need to wipe it. It is probably still in recoveries because you could need it at some point, or developers just didn't remove it yet. 

For me, dalvik cache folder is empty.