def METHOD_NAME(uri):
    """If this is an s3 protocol, discover and return the (aws) region name.
    If a return name could not be discovered, or if the uri is not an s3 protocol, return None."""
    protocol, _ = DataLocator._get_protocol_and_path(uri)
    if protocol == "s3":
        bucket = urlparse(uri).netloc
        client = boto3.client("s3")
        try:
            res = client.head_bucket(Bucket=bucket)
        except botocore.exceptions.ClientError:
            return None
        region = res.get("ResponseMetadata", {}).get("HTTPHeaders", {}).get("x-amz-bucket-region")
        if region:
            return region
        else:
            return None
    return None