code: def add_batch(self, gt_image, pre_image):
      # assert the size of two images are same
      assert gt_image.shape == pre_image.shape
      self.confusion_matrix += self.__generate_matrix(
          gt_image, pre_image
      )
  
imports: import os
  import time
  import tqdm
  import numpy
  from PIL import Image
  import paddle
  import paddle.nn.functional
  from paddleseg.utils import metrics, TimeAverager, calculate_eta, logger, progbar
  import datasets
  from utils import save_imgs
label_desc: Use image node_id 9 for calling the Eval obj's underlying member method code with example usage: obj.add_batch(gt_image, pre_image) without return types