Exports to SavedModel directory.

    Args:
      path: path where to export the SavedModel to.
      variables_saver: lambda that receives a directory path where to
        export checkpoints of variables.

def export(self, path, variables_saver=None):
    """Exports to SavedModel directory.

    Args:
      path: path where to export the SavedModel to.
      variables_saver: lambda that receives a directory path where to
        export checkpoints of variables.
    """
    # Operate on a copy of self._proto since it needs to be modified.
    proto = saved_model_pb2.SavedModel()
    proto.CopyFrom(self._proto)
    assets_map = _make_assets_key_collection(proto, path)

    self._save_all_assets(path, assets_map)
    self._save_variables(path, variables_saver)
    self._save_proto(path, proto)