[{'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:\nbatch_size=80000\nnb_epoch=400\n\nprint(\'Fit model...\')\nfilepath="weights_rossmann.best.hdf5"\ncheckpoint = ModelCheckpoint(filepath, monitor=\'val_rmspe\', verbose=1, save_best_only=True, mode=\'min\')\ncallbacks_list = [checkpoint]\n\nlog = model_m.fit(X_train, y_train,\n          validation_data=(X_test,y_test), batch_size=batch_size ,epochs=nb_epoch, shuffle=True, callbacks=callbacks_list)\''}, {'role': 'assistant', 'content': 'modelling'}]