code: def setUpClass(cls):
      global mtcnn
      mtcnn = MTCNN()
  
file_path: mtcnn/tests/test_mtcnn.py
imports: import unittest
  import cv2
  from mtcnn.exceptions import InvalidImage
  from mtcnn import MTCNN
label_desc: Use image node_id 1 for calling the TestMTCNN obj's underlying member method code with example usage: obj.setUpClass(cls) without return types