[{'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:from sklearn.ensemble import GradientBoostingRegressor\n\ngbr = GradientBoostingRegressor(n_estimators=200, learning_rate=0.9, max_depth = 4)\n\nestimator = pipeline.Pipeline(steps = [       \n    (\'feature_processing\', pipeline.FeatureUnion(transformer_list = transformer_list)),\n    (\'model_fitting\', gbr)\n    ]\n)\nestimator.fit(train_data, train_labels)\n#metrics.mean_absolute_error(test_labels, estimator.predict(test_data))\nprint("RMSLE: ", rmsle(test_labels, estimator.predict(test_data)))\''}, {'role': 'assistant', 'content': 'evaluation'}]