Why is WITH_EDITOR used in UEdGraphSchema?

Below is a screenshot from UnrealEngine\Engine\Source\Runtime\Engine\Private\EdGraph\EdGraphSchema.cpp

Why is WITH_EDITOR used at all in this file? My understanding of the code in EdGraph is that it is only relevant to editor builds that use graphs. I would assume that WITH_EDITOR should apply everywhere. But it is used selectively in this file, which makes me think that I don’t understand the macro very well. Can someone explain?