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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 init_db(self):
 """ This function configures the database used for models to make the configuration parameters. """

        # get the database url from the configuration
        db_url = self.config.get('database_url', 'sqlite:///nautilus.db')
        # configure the nautilus database to the url
        nautilus.database.init_db(db_url)