public interface LargeMessageFormatter<T> extends Configurable {
    LargeMessageFormatter JSON = new LargeMessageFormatter() {
        // implement a default json one
        // format is { 
        //          "full-blob-path": "<full-path-to-access-blob-as-string>",
        //          "blob-store-class": "<used-blob-store-class-path-to-upload-blob>",
        //          "blob-id-generator-class": "<class-used-to-generate-blob-id>",
        //          "large-message-formatter-class": "<formatter-class-path>"
        //        }
    };

    /**
     * build message bytes from blob store response and data.
     */
    byte[] messageBytes(byte[] data, BlobResponse response);

    /**
     * parse data into LargeBlobMessage.
     */
    T largeBlobMessage(byte[] data);
}