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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 dict_to_ddb(item):
 # type: (Dict[str, Any]) -> Dict[str, Any] # TODO: narrow these types down """Converts a native Python dictionary to a raw DynamoDB item. :param dict item: Native item :returns: DynamoDB item :rtype: dict """

    serializer = TypeSerializer()
    return {key: serializer.serialize(value) for key, value in item.items()}