[{'role': 'system', 'content': "You are an expert in machine learning and your task is to classify code snippets into one of the following categories: ['helper_functions', 'load_data', 'data_exploration', 'data_preprocessing', 'evaluation', 'modelling', 'prediction', 'result_visualization', 'save_results', 'comment_only']."}, {'role': 'user', 'content': 'Identify the single most appropriate category to which the provided code belongs. Provide your response as a single category label without any additional information, commentary, or personal opinions.\\nPython Code:train, test = D.get_mnist(ndim=3)  # each image has shape (1, 28, 28)\nbatchsize = 128\ntrain_iter = chainer.iterators.SerialIterator(train, batchsize)\ntest_iter = chainer.iterators.SerialIterator(test, batchsize, repeat=False, shuffle=False)'}, {'role': 'assistant', 'content': 'load_data'}]