code: def test_valid_file():
      # Arrange
      # https://ghrc.nsstc.nasa.gov/hydro/details/cmx3g8
      # https://ghrc.nsstc.nasa.gov/pub/fieldCampaigns/camex3/cmx3g8/browse/
      test_file = "Tests/images/cmx3g8_wv_1998.260_0745_mcidas.ara"
      saved_file = "Tests/images/cmx3g8_wv_1998.260_0745_mcidas.png"
  
      # Act
      with Image.open(test_file) as im:
          im.load()
  
          # Assert
          assert im.format == "MCIDAS"
          assert im.mode == "I"
          assert im.size == (1800, 400)
          assert_image_equal_tofile(im, saved_file)
  
imports: import pytest
  from PIL import Image, McIdasImagePlugin
  from .helper import assert_image_equal_tofile
label_desc: Use image node_id 2 for calling a global function with example usage: test_valid_file() without return types