Activate the same profile on two devices. Arguably, real NetworkManager
(currently) does not allow that. But the D-Bus API is fine with
having multiple ActiveConnections for one SettingsConnection.
So, also the client should do something sensible.
Also, later we will add wildcard support to NetworkManager, which means
that a profile can be active multiple times (simultaneously).
This is purely for (manual) printf debugging. Hence, it is unused in the commited code.
The point is, to add printf statements to nmcli or libnm, like
if (getenv ("MY_HACK1")) { ...
and trigger it from test-client.py via
self.call_nmcli(..., extra_env = { 'MY_HACK1': '1' } )
Add a test which runs nmcli against our stub NetworkManager
service and compares the output.
The output formats of nmcli are complicated and not easily understood.
For example how --mode tabular|multiline interacts with selecting
output-fields (--fields) and output modes ([default]|--terse|--pretty).
Also, there are things like `nmcli connection show --order $FIELD_SPEC`.
We need unit tests to ensure that we don't change the output
accidentally.
