Metrics

     Operand<TInt32> labels = tf.constant(new int[][]
                                    { {0, 0, 1}, {0, 1, 0} });
     Operand<TFloat32> predictions = tf.constant(new float[][]
                                    { {0.1f, 0.9f, 0.8f}, {0.05f, 0.95f, 0f} });
     Operand<TFloat32> m = Metrics.topKCategoricalAccuracy(
                                    labels, predictions, 3)
     //m.shape().toString == "[2]"