Update() only in Edit mode

Hey guys,

I currently have a script attached to a gameobject. It has [ExecuteInEditMode] enabled. This script is supposed to manage some gameobjects during edit mode. Additionally the script is supposed to do nothing during the game itself. I would love to use Update() to do some of the operations, but as far as I know Update is called during the game as well. Is there a way to determine whether you are in Edit mode inside of the script, or another way to solve my problem?

Unity - Scripting API: RuntimePlatform is one way

Unity - Manual: Conditional Compilation is another