message: document ModelBatcher ctor parameters
diff: @@ -57,7 +57,10 @@ class ModelBatcher {
  absl::Notification* notification;
  };
  - ModelBatcher(std::unique_ptr<DualNet> model_impl, size_t buffering);
  + // model_impl: the model that will evaluate the batched inferences.
  + // buffer_count: the model's ideal number of in-flight inference requests, as
  + // returned by the model factory's GetBufferCount() method.
  + ModelBatcher(std::unique_ptr<DualNet> model_impl, size_t buffer_count);
  ~ModelBatcher();
  const std::string& name() const { return model_impl_->name(); }
  