Returns a serialized `GraphDef` representation of this graph. The serialized `GraphDef` can be imported into another `Graph` (using `tf.import_graph_def`) or used with the [C++ Session API](../../api_docs/cc/index.md). This method is thread-safe. Args: from_version: Opti
(self, from_version=None, add_shapes=False)
source not stored for this graph (policy: none)