The function name `for_each_callback` is ambigous (what are we iterating?) and also doesn't align with the naming of other "for each" functions in Blender which usually are named `foreach_<thing>` like `IndexMask::foreach_index` or `animrig::foreach_fcurve_in_action` etc. Pull Request: https://projects.blender.org/blender/blender/pulls/147440