[Need fix] after generator went through optimization update, the pickle state does not work any more

[liyin2015]

# pickle file

# save the serialized states to a file
from adalflow.utils.file_io import save_pickle
states = doc.to_dict()
# save_json(states, "doc.json")
save_pickle(states, "doc.pkl")

# load the serialized states from a file
from adalflow.utils.file_io import load_pickle
states_loaded = load_pickle("doc.pkl")

print(states_loaded == states)

doc_pickle = DocQA.from_dict(states_loaded)

---

AttributeError Traceback (most recent call last)
/usr/local/lib/python3.10/dist-packages/adalflow/utils/file_io.py in save_pickle(obj, f)
64 with open(f, "wb") as file:
---> 65 pickle.dump(obj, file)
66 except Exception as e:

AttributeError: Can't pickle local object 'Generator.set_data_map_func..default_map_func'

During handling of the above exception, another exception occurred:

Exception Traceback (most recent call last)
1 frames
/usr/local/lib/python3.10/dist-packages/adalflow/utils/file_io.py in save_pickle(obj, f)
65 pickle.dump(obj, file)
66 except Exception as e:
---> 67 raise Exception(f"Error saving object to pickle file {f}: {e}")
68
69

Exception: Error saving object to pickle file doc.pkl: Can't pickle local object 'Generator.set_data_map_func..default_map_func'

Will need to have a customized to_dict and 'from_dict` so that we can exclude unpicklable object and restore it at from_dict loading

[sameeramin]

@liyin2015 Does this issue persist? I'm unable to reproduce it. Could you please add a bit more steps to reproduce this bug?