add a versionadded tag for set_tunnel
diff --git a/Doc/library/httplib.rst b/Doc/library/httplib.rst
index 9a5acc1..bf7e8ef 100644
--- a/Doc/library/httplib.rst
+++ b/Doc/library/httplib.rst
@@ -433,6 +433,8 @@
    Set the host and the port for HTTP Connect Tunnelling. Normally used when
    it is required to do HTTPS Conection through a proxy server.
 
+   .. versionadded:: 2.7
+
 
 .. method:: HTTPConnection.connect()