def ensure_defaults(self, alias):
        """
        Puts the defaults into the settings dictionary for a given connection
        where no settings is provided.
        """
        try:
            conn = self.databases[alias]
        except __HOLE__:
            raise ConnectionDoesNotExist("The connection %s doesn't exist" % alias)

        conn.setdefault('ATOMIC_REQUESTS', False)
        conn.setdefault('AUTOCOMMIT', True)
        conn.setdefault('ENGINE', 'django.db.backends.dummy')
        if conn['ENGINE'] == 'django.db.backends.' or not conn['ENGINE']:
            conn['ENGINE'] = 'django.db.backends.dummy'
        conn.setdefault('CONN_MAX_AGE', 0)
        conn.setdefault('OPTIONS', {})
        conn.setdefault('TIME_ZONE', None)
        for setting in ['NAME', 'USER', 'PASSWORD', 'HOST', 'PORT']:
            conn.setdefault(setting, '')
dataset/ETHPy150Open django/django/django/db/utils.py/ConnectionHandler.ensure_defaults