I'm working on a simple editor script that groups/ungroups objects under a new parent empty transform. I'm using Undo.SetTransformParent and it works great for regular objects. For children of prefab instances, it simply fails silently. This is consistent with the limitation imposed by the hierarchy drag & drop. However, the hierarchy gives me this nice warning: Is there a specific API I could use to get the same warning, or at least check whether a given GameObject/Transform is restructurable? This way I could abort the grouping operation early before creating an unusable parent game object.