public SDVariable sigmoidCrossEntropy(SDVariable label, SDVariable predictionLogits,
      SDVariable weights, LossReduce lossReduce, double labelSmoothing) {
    SDValidation.validateNumerical("sigmoidCrossEntropy", "label", label);
    SDValidation.validateNumerical("sigmoidCrossEntropy", "predictionLogits", predictionLogits);
    SDValidation.validateNumerical("sigmoidCrossEntropy", "weights", weights);