ofono template: cannot add second modem

When trying to add a second modem to a ofono mock (using the template), it fails.

Minimal test case:
http://pastebin.ubuntu.com/7779081/

Ouput:
http://pastebin.ubuntu.com/7779083/

The exception is:
    DBusException: org.freedesktop.DBus.Python.dbus.exceptions.DBusException: ('org.freedesktop.DBus.Mock.NameError', 'object /ril_0/operator/op1 already exists')

Which comes from AddModem calling add_netreg_api, which tries to add an object like so:
    mock.AddObject('/%s/operator/op1' % _parameters.get('ModemName', 'ril_0'),

_parameters seems to be unchangeable from the test case, or, most likely, I am using this code wrong.

ProblemType: Bug
DistroRelease: Ubuntu 14.10
Package: python3-dbusmock (not installed)
ProcVersionSignature: Ubuntu 3.15.0-6.11-generic 3.15.0
Uname: Linux 3.15.0-6-generic x86_64
ApportVersion: 2.14.4-0ubuntu1
Architecture: amd64
CurrentDesktop: Unity
Date: Fri Jul 11 10:02:08 2014
DistributionChannelDescriptor:
 # This is a distribution channel descriptor
 # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor
 canonical-oem-somerville-precise-amd64-20120703-2
EcryptfsInUse: Yes
InstallationDate: Installed on 2013-08-27 (317 days ago)
InstallationMedia: Ubuntu 12.04 "Precise" - Build amd64 LIVE Binary 20120703-15:08
SourcePackage: python-dbusmock
UpgradeStatus: Upgraded to utopic on 2014-07-01 (9 days ago)