code: def test_variable_fps_seek(test_images):
      with iio.imopen(
          test_images / "cockatoo.mp4", "r", plugin="pyav"
      ) as file:
          expected = iio.imread(
              test_images / "cockatoo.mp4", index=15, plugin="pyav"
          )
          actual = file.read(index=15, constant_framerate=False)
          assert np.allclose(actual, expected)
  
          expected = iio.imread(
              test_images / "cockatoo.mp4", index=3, plugin="pyav"
          )
          actual = file.read(index=3, constant_framerate=False)
  
          assert np.allclose(actual, expected)
  
      meta = iio.immeta(
          test_images / "cockatoo.mp4",
          index=3,
          plugin="pyav",
          constant_framerate=False,
      )
      assert meta["interlaced_frame"] is False
  
imports: import io
  import warnings
  from contextlib import ExitStack
  from pathlib import Path
  import numpy
  import pytest
  from conftest import IS_PYPY
  import imageio.v3
  from av.video.format import names
  from imageio.plugins.pyav import _format_to_dtype
label_desc: Use image node_id 15 for calling a global function with example usage: test_variable_fps_seek(test_images) without return types