Whether the backend has reached a quiescent state. This will happen at some point after Backend.prepare has successfully completed for the backend. A backend is in a quiescent state when all the PersonaStores that it originally knows about have been loaded.
It's guaranteed that this property's value will only ever change after
Backend.is_prepared has changed to true.
When Backend.unprepare is called, this will be reset to false
.
0.6.2