docs: public SDVariable meanSquaredError(String name, @NonNull SDVariable label, @NonNull SDVariable predictions,
                                         SDVariable weights, @NonNull LossReduce lossReduce) {
          validateFloatingPoint("mean squared error loss", "predictions", predictions);
          validateNumerical("mean squared error loss", "labels", label);
          if (weights == null)
              weights = sd.scalar(null, predictions.dataType(), 1.0);
          SDVariable result = f().lossMeanSquaredError(label, predictions, weights, lossReduce);
          result = updateVariableNameAndReference(result, name);
          result.markAsLoss();
          return result;
      }