Creating a gtk.Settings object with a different backend allows accessing
settings from a database other than the usual one. For example, it may make
sense to pass a backend corresponding to the "defaults" settings database on
the system to get a settings object that modifies the system default
settings instead of the settings for this user.
Creates a new gtk.Settings object with the schema specified by schema_id and a given gio.SettingsBackend
Creating a gtk.Settings object with a different backend allows accessing settings from a database other than the usual one. For example, it may make sense to pass a backend corresponding to the "defaults" settings database on the system to get a settings object that modifies the system default settings instead of the settings for this user.