code: def normalize(self, normalize_numpy, mask_numpy=None):
      return normalize_numpy
  
imports: import subprocess
  import os
  import numpy
  from deepneuro.preprocessing.preprocessor import Preprocessor
  from deepneuro.utilities.conversion import read_image_files
  from deepneuro.utilities.util import add_parameter, quotes
label_desc: Use image node_id 3 for calling the Normalization obj's underlying member method code with example usage: obj.normalize(normalize_numpy, mask_numpy) and returns: normalize_numpy