<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def deserialize(obj):
 """Convert JSON dicts back into objects."""

    # Be careful of shallow copy here
    target = dict(obj)
    class_name = None
    if '__class__' in target:
        class_name = target.pop('__class__')
    if '__module__' in obj:
        obj.pop('__module__')
    # Use getattr(module, class_name) for custom types if needed
    if class_name == 'datetime':
        return datetime.datetime(tzinfo=utc, **target)
    if class_name == 'StreamingBody':
        return StringIO(target['body'])
    # Return unrecognized structures as-is
    return obj