how to fix the warning message always displayed when I want to classify images after augmentation process, the worning message is about preallocating

I have dataset of x-ray images, and I want to classify the dataset to normal and not_normal. I have used the augmentation process as shown in the following script:

augmenter = imageDataAugmenter( ...

'RandRotation',[-5 5],'RandXReflection',1,...

'RandYReflection',1,'RandXShear',[-0.05 0.05],'RandYShear',[-0.05 0.05]);

auimds = augmentedImageDatastore([224 224],imdsTrain,'DataAugmentation',augmenter);

netTransfer=trainNetwork(auimds,lgraph,options);

augtestimds=augmentedImageDatastore([224 224],imdsTest);

[predicted_labels(test_idx),posterior(test_idx,:)] = classify(netTransfer,augtestimds);

But every time there is a warning message appeare on the last statement, which is: [predicted_labels(test_idx),posterior(test_idx,:)] = classify(netTransfer,augtestimds);

The warning message said that the variable 'posterior' appears to change size on every loop iteration (within a script). consider preallocating for speed.

How can fix this issue?

Thanks in advance