Use setattr magic to fix NeuralNet pickle error elegantly

app.py

@@ -1,6 +1,11 @@
 import gradio as gr
 from PIL import Image
 import os
+import sys
+
+import defake.test_api
+# 把 defake.test_api 里的 NeuralNet 类，“挂载”到当前的主模块 (__main__) 上
+setattr(sys.modules['__main__'], 'NeuralNet', defake.test_api.NeuralNet)
 
 from app_infer import run_infer_from_image