code: def test_target_frame(self, ucsd_dataset):
      ucsd_dataset.target_frame = VideoTargetFrame.ALL
      all_frames_item = ucsd_dataset[0]
      ucsd_dataset.target_frame = VideoTargetFrame.FIRST
      first_frame_item = ucsd_dataset[0]
      ucsd_dataset.target_frame = VideoTargetFrame.LAST
      last_frame_item = ucsd_dataset[0]
      ucsd_dataset.target_frame = VideoTargetFrame.MID
      mid_frame_item = ucsd_dataset[0]
  
      # check if the correct GT frame is retrieved
      assert first_frame_item["frames"] == all_frames_item["frames"][0]
      assert last_frame_item["frames"] == all_frames_item["frames"][-1]
      assert (
          mid_frame_item["frames"]
          == all_frames_item["frames"][
              int(len(all_frames_item["frames"]) / 2)
          ]
      )
  
file_path: anomalib/tests/pre_merge/datasets/test_video.py
imports: from pathlib import Path
  import pytest
  from anomalib.data import TaskType
  from anomalib.data.base.video import VideoTargetFrame
  from anomalib.data.ucsd_ped import UCSDpedClipsIndexer, UCSDpedDataset, make_ucsd_dataset
  from anomalib.data.utils import get_transforms
  from anomalib.data.utils.split import Split, random_split
  from tests.helpers.dataset import get_dataset_path
label_desc: Use image node_id 3 for calling the TestVideoDataset obj's underlying member method code with example usage: obj.test_target_frame(ucsd_dataset) without return types