def test_getRawHeaders(self):
        """
        L{Headers.getRawHeaders} returns the values which have been set for a
        given header.
        """
        h = Headers()
        h.setRawHeaders(b"test", [b"lemur"])
        self.assertEqual(h.getRawHeaders(b"test"), [b"lemur"])
        self.assertEqual(h.getRawHeaders(b"Test"), [b"lemur"])

        L{Headers.getRawHeaders} returns the values which have been set for a
        given header.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/test/test_http_headers.py