code: def visualize(self):
      pass
  
imports: import os
  import os.path
  import sys
  import time
  import glob
  import numpy
  import nibabel
  import SimpleITK
  from tqdm import tqdm
  import json
  from medicalseg.utils import get_image_list
  from tools.preprocess_utils import uncompressor, global_var, add_qform_sform, join_paths
label_desc: Use image node_id 7 for calling the Prep obj's underlying member method code with example usage: obj.visualize() without return types