def test_coverage(self):
        """
        L{WorkerOptions.coverdir} returns the C{coverage} child directory of
        the current directory to be used for storing coverage data.
        """
        self.assertEqual(
            os.path.realpath(os.path.join(os.getcwd(), "coverage")),
            self.options.coverdir().path)

        L{WorkerOptions.coverdir} returns the C{coverage} child directory of
        the current directory to be used for storing coverage data.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/trial/_dist/test/test_options.py