<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(self, obj):
 """Deserialize an object from the front-end."""

        if obj['immutable']:
            return obj['value']
        else:
            guid = obj['value']
            if not guid in object_registry:
                instance = JSObject(self, guid)
                object_registry[guid] = instance
            return object_registry[guid]