code: def test_read_timestamps_pts_unit_sec(self):
      with temp_video(10, 300, 300, 5) as (f_name, data):
          pts, _ = io.read_video_timestamps(f_name, pts_unit="sec")
  
          with av.open(f_name) as container:
              stream = container.streams[0]
              pts_step = int(
                  round(
                      float(
                          1 / (stream.average_rate * stream.time_base)
                      )
                  )
              )
              num_frames = int(
                  round(
                      float(
                          stream.average_rate
                          * stream.time_base
                          * stream.duration
                      )
                  )
              )
              expected_pts = [
                  i * pts_step * stream.time_base
                  for i in range(num_frames)
              ]
  
          assert pts == expected_pts
  
imports: import contextlib
  import os
  import sys
  import tempfile
  import pytest
  import torch
  import torchvision.io
  from common_utils import assert_equal
  from torchvision import get_video_backend
label_desc: Use image node_id 10 for calling the TestVideo obj's underlying member method code with example usage: obj.test_read_timestamps_pts_unit_sec() without return types