code: def test_init(self):
      bbox_head = MultiInstanceBBoxHead(
          num_instance=2,
          with_refine=True,
          num_shared_fcs=2,
          in_channels=1,
          fc_out_channels=1,
          num_classes=4,
      )
      self.assertTrue(bbox_head.shared_fcs_ref)
      self.assertTrue(bbox_head.fc_reg)
      self.assertTrue(bbox_head.fc_cls)
      self.assertEqual(len(bbox_head.shared_fcs), 2)
      self.assertEqual(len(bbox_head.fc_reg), 2)
      self.assertEqual(len(bbox_head.fc_cls), 2)
  
file_path: mmdetection/tests/test_models/test_roi_heads/test_bbox_heads/test_multi_instance_bbox_head.py
imports: from unittest import TestCase
  import torch
  from mmengine.config import ConfigDict
  from mmengine.structures import InstanceData
  from mmdet.models.roi_heads.bbox_heads import MultiInstanceBBoxHead
label_desc: Use image node_id 1 for calling the TestMultiInstanceBBoxHead obj's underlying member method code with example usage: obj.test_init() without return types