[python3] missing twisted.conch.client, twisted.conch.ssh missing: transport, userauth, connection, channel, forwarding

[Adrian]

I try to upgrade my script utilizing twisted to python3.
However,
 twisted.conch.client module is missing
 twisted.conch.ssh is missing transport, userauth, connection, channel, forwarding

All names are available in python2.7 which provides twisted library in the same version (16.0.0) as python3.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: python3-twisted 16.0.0-1
ProcVersionSignature: Ubuntu 4.4.0-23.41-generic 4.4.10
Uname: Linux 4.4.0-23-generic x86_64
NonfreeKernelModules: openafs
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
CurrentDesktop: Unity
Date: Tue May 24 13:26:44 2016
InstallationDate: Installed on 2015-04-02 (417 days ago)
InstallationMedia: Ubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
PackageArchitecture: all
SourcePackage: twisted
UpgradeStatus: Upgraded to xenial on 2016-04-26 (27 days ago)