code: def setUpClass(cls):
      register_all_modules(init_default_scope=True)
      cls.num_objs = 30
  
file_path: mmdetection/tests/test_models/test_trackers/test_sort_tracker.py
imports: from unittest import TestCase
  from unittest.mock import MagicMock
  import torch
  from parameterized import parameterized
  from mmdet.registry import MODELS, TASK_UTILS
  from mmdet.testing import demo_track_inputs, get_detector_cfg, random_boxes
  from mmdet.utils import register_all_modules
label_desc: Use image node_id 1 for calling the TestSORTTracker obj's underlying member method code with example usage: obj.setUpClass(cls) without return types