def value_to_response(self, dispatcher, prop_xml_name, value, path):

        if((len(path) > 0) and (path.pop(0) == CONTENT_PATH)):
            blob_info = None
            if value:
                blob_info = blobstore.BlobInfo.get(value)
            dispatcher.serve_blob(blob_info)
            return

        # just return blobinfo key
        super(BlobReferenceHandler, self).value_to_response(
            dispatcher, prop_xml_name, value, path)
Writes the output a blobkey property (or the blob contents) to the
dataset/ETHPy150Open jahlborn/appengine-rest-server/src/main/python/rest/__init__.py/BlobReferenceHandler.value_to_response