'Puts the defaults into the settings dictionary for a given connection
where no settings is provided.'

def ensure_defaults(self, alias):

    try:
        conn = self.databases[alias]
    except KeyError:
        raise ConnectionDoesNotExist(("The    connection    %s    doesn't    exist" % alias))
    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('OPTIONS', {})
    conn.setdefault('TIME_ZONE', ('UTC' if settings.USE_TZ else settings.TIME_ZONE))
    for setting in ['NAME', 'USER', 'PASSWORD', 'HOST', 'PORT']:
        conn.setdefault(setting, '')
    for setting in ['TEST_CHARSET', 'TEST_COLLATION', 'TEST_NAME', 'TEST_MIRROR']:
        conn.setdefault(setting, None)
