Why deepcopy __dict__ to serialize to json?

[melsabagh]

The deepcopy of the instance __dict__ during serialization at the following line seems unnecessary:

jschema-to-python/jschema_to_python/to_json.py

Line 26 in c4fb418

dict = copy.deepcopy(dict)

I have benchmarked this and it is also a serious bottleneck when serializing large objects. Is there a reason behind creating a deep copy here instead of a shallow copy?