code: def test_union_with_mixed_files_fails(self) -> None:
      run1 = TestRun("foo")
      run2 = TestRun("bar")
  
      with self.assertRaises(AssertionError):
          run1 | run2
  
imports: import pathlib
  import sys
  import unittest
label_desc: Use image node_id 6 for calling the TestTestRun obj's underlying member method code with example usage: obj.test_union_with_mixed_files_fails() without return types