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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 create_batch_write_structure(table_name, start_num, num_items):
 """ Create item structure for passing to batch_write_item :param table_name: DynamoDB table name :type table_name: str :param start_num: Start index :type start_num: int :param num_items: Number of items :type num_items: int :return: dictionary of tables to write to :rtype: dict """

    return {
        table_name: [
            {'PutRequest': {'Item': item}}
            for item in get_items(start_num, num_items)
        ]
    }