code: def test_metadata(self, video_file):
      torchvision.set_video_backend("cuda")
      full_path = os.path.join(VIDEO_DIR, video_file)
      decoder = VideoReader(full_path)
      video_metadata = decoder.get_metadata()["video"]
      with av.open(full_path) as container:
          video = container.streams.video[0]
          av_duration = float(video.duration * video.time_base)
          assert math.isclose(
              video_metadata["duration"], av_duration, rel_tol=1e-2
          )
          assert math.isclose(
              video_metadata["fps"], video.base_rate, rel_tol=1e-2
          )
  
file_path: vision/test/test_video_gpu_decoder.py
imports: import math
  import os
  import pytest
  import torch
  import torchvision
  from torchvision.io import _HAS_GPU_VIDEO_DECODER, VideoReader
label_desc: Use image node_id 3 for calling the TestVideoGPUDecoder obj's underlying member method code with example usage: obj.test_metadata(video_file) without return types