code: def test_init(self):
      fake_json_file = osp.join(self.tmp_dir.name, "fake_data.json")
      self._create_dummy_lvis_json(fake_json_file)
      with self.assertRaisesRegex(KeyError, "metric should be one of"):
          LVISMetric(ann_file=fake_json_file, metric="unknown")
  
imports: import os.path
  import tempfile
  import unittest
  import numpy
  import pycocotools.mask
  import torch
  from mmdet.evaluation.metrics import LVISMetric
  from mmengine.fileio import dump
label_desc: Use image node_id 5 for calling the TestLVISMetric obj's underlying member method code with example usage: obj.test_init() without return types