code: def test_cmpfiles(self):
      self.assertTrue(
          filecmp.cmpfiles(self.dir, self.dir, ["file"])
          == (["file"], [], []),
          "Comparing directory to itself fails",
      )
      self.assertTrue(
          filecmp.cmpfiles(self.dir, self.dir_same, ["file"])
          == (["file"], [], []),
          "Comparing directory to same fails",
      )
  
      # Try it with shallow=False
      self.assertTrue(
          filecmp.cmpfiles(self.dir, self.dir, ["file"], shallow=False)
          == (["file"], [], []),
          "Comparing directory to itself fails",
      )
      self.assertTrue(
          filecmp.cmpfiles(
              self.dir, self.dir_same, ["file"], shallow=False
          ),
          "Comparing directory to same fails",
      )
  
      # Add different file2
      with open(
          os.path.join(self.dir, "file2"), "w", encoding="utf-8"
      ) as output:
          output.write("Different contents.\n")
  
      self.assertFalse(
          filecmp.cmpfiles(self.dir, self.dir_same, ["file", "file2"])
          == (["file"], ["file2"], []),
          "Comparing mismatched directories fails",
      )
  
imports: import filecmp
  import os
  import shutil
  import tempfile
  import unittest
  from test import support
  from test.support import os_helper
label_desc: Use image node_id 4 for calling the DirCompareTestCase obj's underlying member method code with example usage: obj.test_cmpfiles() without return types