message: Added note that gradient accumulation is experimental.
diff: @@ -119,7 +119,9 @@ message OptimizationParameters {
  // Whether to use gradient accumulation (do two passes over the input
  // gradients: one to accumulate them into a temporary array and another to
  - // apply them using the actual optimization algorithm).
  + // apply them using the actual optimization algorithm). This feature is
  + // experimental -- it has not been fully verified and may cause training
  + // crashes and/or failures.
  bool use_gradient_accumulation = 15;
  // Optimization algorithm parameters; which field is selected determines which
  