[Python] EditorActorSubsystem.on_new_actors_placed.add_callable will crash editor

Development Programming & Scripting
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1

The test code I use:

import unreal
def test_func(object, actors):
    print('hello')
unreal.get_editor_subsystem(unreal.EditorActorSubsystem).on_new_actors_placed.add_callable(test_func)

Then place an actor into scene, and the editor will crash.
The problem seems like the on_new_actors_placed function have two parameter object_to_use and placed_actors, while placed_actors has flag CPF_OutParm but on_new_actors_placed has no flag CPF_ReturnParm

In PyGenUtil.cpp line 1183 in function InvokePythonCallableFromUnrealFunctionThunk
InFunc have no return property, so it crashes at line 1216, where FOutParmRec OutParms* is needed. I have no idea how to fix this problem. Any Help?