[{'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:def style_loss(style, combination):\nS = gram_matrix(style)\nC = gram_matrix(combination)\nchannels = 3\nsize = height * width\nreturn backend.sum(backend.square(S - C)) / (4. * (channels ** 2) * (size ** 2))\nfeature_layers = ['block1_conv2', 'block2_conv2',\n'block3_conv3', 'block4_conv3',\n'block5_conv3']\nfor layer_name in feature_layers:\nlayer_features = layers[layer_name]\nstyle_features = layer_features[1, :, :, :]\ncombination_features = layer_features[2, :, :, :]\nsl = style_loss(style_features, combination_features)\nloss += (style_weight / len(feature_layers)) * sl"}, {'role': 'assistant', 'content': 'modelling'}]