code: def centerx(self):
      return (self.rect[0] + self.rect[2]) * 0.5
  
imports: import csv
  import multiprocessing
  import os
  import re
  import nnabla.logger
  import numpy
  import tqdm
  from nnabla.utils.image_utils import imsave, imread, imresize
label_desc: Use image node_id 9 for calling the ObjectRect obj's underlying member method code with example usage: obj.centerx() and returns: unknown