message: Deterministic sort of keras network _checkpoint_dependencies to enable MultiWorkerMirroredStrategy checkpointing and prevent different tensors being broadcast for the same CollectiveOps key.
diff: @@ -411,7 +411,7 @@ class Network(base_layer.Layer):
  def _checkpoint_dependencies(self):
  dependencies = [
  trackable.TrackableReference(name=name, ref=layer)
  - for name, layer in self._layer_checkpoint_dependencies.items()]
  + for name, layer in sorted(self._layer_checkpoint_dependencies.items())]
  dependencies.extend(super(Network, self)._checkpoint_dependencies)
  return dependencies
  