def test_addRawHeader(self):
        """
        L{Headers.addRawHeader} adds a new value for a given header.
        """
        h = Headers()
        h.addRawHeader(u"test", u"lemur")
        self.assertEqual(h.getRawHeaders(u"test"), [u"lemur"])
        h.addRawHeader(u"test", u"panda")
        self.assertEqual(h.getRawHeaders(u"test"), [u"lemur", u"panda"])
        self.assertEqual(h.getRawHeaders(b"test"), [b"lemur", b"panda"])

        L{Headers.addRawHeader} adds a new value for a given header.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/test/test_http_headers.py