Gio.TestDBus.prototype.up
function up(): void { // Gjs wrapper for g_test_dbus_up() }
Start a dbus-daemon instance and set DBUS_SESSION_BUS_ADDRESS. After this call, it is safe for unit tests to start sending messages on the session bus.
If this function is called from setup callback of g_test_add(), Gio.TestDBus.prototype.down must be called in its teardown callback.
If this function is called from unit test's main(), then Gio.TestDBus.prototype.down must be called after GLib.test_run.