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Fix class spacing in test_filecmp per PEP 8

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>

Author: Bolotnyj

Lib/test/test_filecmp.py

@@ -95,6 +95,7 @@ def test_cache_overflow_and_hit(self):
         res2 = filecmp.cmp(self.name, self.name_same, shallow=False)
         self.assertTrue(res2)
 
+
 class DirCompareTestCase(unittest.TestCase):
     def setUp(self):
         tmpdir = tempfile.gettempdir()