[{'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:out_path = '/data1/abide/legacy_test/mean_centered_old1.nii.gz'\nold_1 = np.zeros_like(mask, dtype=float)\nold_1[mask] = stack[0,:,0]\nold_img = nib.Nifti1Image(old_1, header=m_img.get_header(), affine=m_img.get_affine())\nnib.save(old_img, out_path)"}, {'role': 'assistant', 'content': 'data_preprocessing'}]