public INDArray meanPairwiseSquaredError(INDArray label, INDArray predictions, INDArray weights,
      LossReduce lossReduce) {
    NDValidation.validateNumerical("meanPairwiseSquaredError", "label", label);
    NDValidation.validateNumerical("meanPairwiseSquaredError", "predictions", predictions);
    NDValidation.validateNumerical("meanPairwiseSquaredError", "weights", weights);