code: def setUp(self):
      init_default_scope("mmdet")
      cfg = Config(
          dict(
              type="QuasiDenseTrackHead",
              roi_extractor=dict(
                  type="SingleRoIExtractor",
                  roi_layer=dict(
                      type="RoIAlign", output_size=7, sampling_ratio=0
                  ),
                  out_channels=256,
                  featmap_strides=[4, 8, 16, 32],
              ),
              embed_head=dict(
                  type="QuasiDenseEmbedHead",
                  num_convs=4,
                  num_fcs=1,
                  embed_channels=256,
                  norm_cfg=dict(type="GN", num_groups=32),
                  loss_track=dict(
                      type="MultiPosCrossEntropyLoss", loss_weight=0.25
                  ),
                  loss_track_aux=dict(
                      type="MarginL2Loss",
                      neg_pos_ub=3,
                      pos_margin=0,
                      neg_margin=0.1,
                      hard_mining=True,
                      loss_weight=1.0,
                  ),
              ),
              loss_bbox=dict(type="L1Loss", loss_weight=1.0),
              train_cfg=dict(
                  assigner=dict(
                      type="MaxIoUAssigner",
                      pos_iou_thr=0.7,
                      neg_iou_thr=0.5,
                      min_pos_iou=0.5,
                      match_low_quality=False,
                      ignore_iof_thr=-1,
                  ),
                  sampler=dict(
                      type="CombinedSampler",
                      num=256,
                      pos_fraction=0.5,
                      neg_pos_ub=3,
                      add_gt_as_proposals=True,
                      pos_sampler=dict(
                          type="InstanceBalancedPosSampler"
                      ),
                      neg_sampler=dict(type="RandomSampler"),
                  ),
              ),
          )
      )
      self.track_head = MODELS.build(cfg)
  
file_path: mmdetection/tests/test_models/test_tracking_heads/test_quasi_dense_track_head.py
imports: from unittest import TestCase
  import torch
  from mmengine import init_default_scope
  from mmengine.config import Config
  from mmengine.structures import InstanceData
  from mmdet.registry import MODELS
  from mmdet.testing import demo_track_inputs, random_boxes
label_desc: Use image node_id 1 for calling the TestQuasiDenseTrackHead obj's underlying member method code with example usage: obj.setUp() without return types