code: def test_add_meta(self):
      packer = TextDetPacker(data_root=self.root.name, split="test")
      instance = packer.pack_instance(self.sample)
      meta = packer.add_meta(instance)
      self.assertDictEqual(
          meta["metainfo"],
          {
              "dataset_type": "TextDetDataset",
              "task_name": "textdet",
              "category": [{"id": 0, "name": "text"}],
          },
      )
  
file_path: mmocr/tests/test_datasets/test_preparers/test_packers/test_textdet_packer.py
imports: import os.path
  import tempfile
  import unittest
  import cv2
  import numpy
  from mmocr.datasets.preparers import TextDetPacker
label_desc: Use image node_id 3 for calling the TestTextDetPacker obj's underlying member method code with example usage: obj.test_add_meta() without return types