<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, target_obj, data):
 """Call the deserializer on a model. Data needs to be already deserialized as JSON or XML ElementTree :param str target_obj: Target data type to deserialize to. :param object data: Object to deserialize. :raises: DeserializationError if deserialization fails. :return: Deserialized object. """

        # This is already a model, go recursive just in case
        if hasattr(data, "_attribute_map"):
            constants = [name for name, config in getattr(data, '_validation', {}).items()
                         if config.get('constant')]
            try:
                for attr, mapconfig in data._attribute_map.items():
                    if attr in constants:
                        continue
                    value = getattr(data, attr)
                    if value is None:
                        continue
                    local_type = mapconfig['type']
                    internal_data_type = local_type.strip('[]{}')
                    if internal_data_type not in self.dependencies or isinstance(internal_data_type, Enum):
                        continue
                    setattr(
                        data,
                        attr,
                        self._deserialize(local_type, value)
                    )
                return data
            except AttributeError:
                return

        response, class_name = self._classify_target(target_obj, data)

        if isinstance(response, basestring):
            return self.deserialize_data(data, response)
        elif isinstance(response, type) and issubclass(response, Enum):
            return self.deserialize_enum(data, response)

        if data is None:
            return data
        try:
            attributes = response._attribute_map
            d_attrs = {}
            for attr, attr_desc in attributes.items():
                # Check empty string. If it's not empty, someone has a real "additionalProperties"...
                if attr == "additional_properties" and attr_desc["key"] == '':
                    continue
                raw_value = None
                # Enhance attr_desc with some dynamic data
                attr_desc = attr_desc.copy() # Do a copy, do not change the real one
                internal_data_type = attr_desc["type"].strip('[]{}')
                if internal_data_type in self.dependencies:
                    attr_desc["internalType"] = self.dependencies[internal_data_type]

                for key_extractor in self.key_extractors:
                    found_value = key_extractor(attr, attr_desc, data)
                    if found_value is not None:
                        if raw_value is not None and raw_value != found_value:
                            raise KeyError('Use twice the key: "{}"'.format(attr))
                        raw_value = found_value

                value = self.deserialize_data(raw_value, attr_desc['type'])
                d_attrs[attr] = value
        except (AttributeError, TypeError, KeyError) as err:
            msg = "Unable to deserialize to object: " + class_name
            raise_with_traceback(DeserializationError, msg, err)
        else:
            additional_properties = self._build_additional_properties(attributes, data)
            return self._instantiate_model(response, d_attrs, additional_properties)