code: def test_load_file(self):
      filename = temp_filename(self.tempdir, ".jpg")
  
      im = pyvips.Image.black(10, 20)
      im.write_to_file(filename)
  
      x = pyvips.Image.new_from_file(filename)
      assert x.width == 10
      assert x.height == 20
      assert x.bands == 1
  
      os.remove(x.filename)
  
file_path: pyvips/tests/test_saveload.py
imports: import os
  import tempfile
  import pytest
  import pyvips
  from helpers import temp_filename, skip_if_no, _is_PY3, IMAGES, JPEG_FILE
label_desc: Use image node_id 3 for calling the TestSaveLoad obj's underlying member method code with example usage: obj.test_load_file() without return types