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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _classify(cls, response, objects):
 """Check the class _subtype_map for any child classes. We want to ignore any inherited _subtype_maps. Remove the polymorphic key from the initial data. """

        for subtype_key in cls.__dict__.get('_subtype_map', {}).keys():
            subtype_value = None

            rest_api_response_key = cls._get_rest_key_parts(subtype_key)[-1]
            subtype_value = response.pop(rest_api_response_key, None) or response.pop(subtype_key, None)
            if subtype_value:
                # Try to match base class. Can be class name only
                # (bug to fix in Autorest to support x-ms-discriminator-name)
                if cls.__name__ == subtype_value:
                    return cls
                flatten_mapping_type = cls._flatten_subtype(subtype_key, objects)
                try:
                    return objects[flatten_mapping_type[subtype_value]]
                except KeyError:
                    _LOGGER.warning(
                        "Subtype value %s has no mapping, use base class %s.",
                        subtype_value,
                        cls.__name__,
                    )
                    break
            else:
                _LOGGER.warning(
                    "Discriminator %s is absent or null, use base class %s.",
                    subtype_key,
                    cls.__name__
                )
                break
        return cls