code: def test_n_frames(self):
      for path, n_frames in [
          ["Tests/images/multipage-lastframe.tif", 1],
          ["Tests/images/multipage.tiff", 3],
      ]:
          with Image.open(path) as im:
              assert im.n_frames == n_frames
              assert im.is_animated == (n_frames != 1)
  
imports: import os
  from io import BytesIO
  import pytest
  from PIL import Image, ImageFile, TiffImagePlugin
  from PIL.TiffImagePlugin import RESOLUTION_UNIT, X_RESOLUTION, Y_RESOLUTION
  from .helper import assert_image_equal, assert_image_equal_tofile, assert_image_similar, assert_image_similar_tofile, hopper, is_pypy, is_win32
label_desc: Use image node_id 24 for calling the TestFileTiff obj's underlying member method code with example usage: obj.test_n_frames() without return types