def get_objects(client, keys):
    """Retrieve objects from configured memcached under specified keys

    :param client: memcache client object
    :param keys: list of strings
    :return: direct bytestream, no need to read from buffer. If error or timeout, return None.
    """
    objects = client.get_multi(keys)
    if bool(objects):
        return objects
    else:
        return None