def test_maybe_finalize_headers(self, write_method):
writer = HttpWriter(None, None, None, None)
writer._maybe_send_headers()
write_method.assert_called_with(b'\r\n')
writer = HttpWriter(None, None, None, None)
writer._headers_sent = True
writer._maybe_send_headers()
self.assertTrue(writer._headers_sent)
