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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 setup(settings):
 """ Setup the database connection. """

    connector = settings.get('db_connector')
    if connector == 'postgres':
        from playhouse.pool import PooledPostgresqlExtDatabase
        return PooledPostgresqlExtDatabase(settings['db_name'],
                           user=settings['db_user'],
                           password=settings['db_password'],
                           host=settings['db_host'],
                           port=settings.get('db_port'),
                           max_connections=settings.get('db_max_conn'),
                           stale_timeout=settings.get('db_stale_timeout'),
                           timeout=settings.get('db_timeout'),
                           register_hstore=False)