def test_openForReadingNotFound(self):
        """
        openForReading should fail with a C{ftp.FileNotFoundError} on a file
        that doesn't exist.
        """
        d = self.shell.openForReading(('ned',))
        return self.assertFailure(d, ftp.FileNotFoundError)

        openForReading should fail with a C{ftp.FileNotFoundError} on a file
        that doesn't exist.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_ftp.py