If I run the gdbus command right after login (with no menus) then it's just this -
$ gdbus call --session --dest com.canonical.Unity.Panel.Service.Desktop --object-path /com/canonical/Unity/Panel/Service --method com.canonical.Unity.Panel.Service.SyncOne 'libappmenu.so'
([('libappmenu.so', '', '', uint32 0, '', false, false, uint32 0, '', false, false, -1)],)
If I run the gdbus command right after login (with no menus) then it's just this - Unity.Panel. Service. Desktop --object-path /com/canonical/ Unity/Panel/ Service --method com.canonical. Unity.Panel. Service. SyncOne 'libappmenu.so'
$ gdbus call --session --dest com.canonical.
([('libappmenu.so', '', '', uint32 0, '', false, false, uint32 0, '', false, false, -1)],)