Append HTTPSHandler to __all__ when it is available.
diff --git a/Lib/urllib/request.py b/Lib/urllib/request.py
index 97fd544..d360966 100644
--- a/Lib/urllib/request.py
+++ b/Lib/urllib/request.py
@@ -1200,6 +1200,8 @@
 
         https_request = AbstractHTTPHandler.do_request_
 
+    __all__.append(HTTPSHandler)
+
 class HTTPCookieProcessor(BaseHandler):
     def __init__(self, cookiejar=None):
         import http.cookiejar