App\Providers\UserServiceProvider::boot PHP Method

    public function boot()
    {
        // set guest's display name
        Guest::setName($this->app['config']['xe.user.guest.name']);
        // set guest's default profile image
        Guest::setDefaultProfileImage($this->app['config']['xe.user.profileImage.default']);
        // set unknown's display name
        UnknownUser::setName($this->app['config']['xe.user.unknown.name']);
        // set unknown's default profile image
        UnknownUser::setDefaultProfileImage($this->app['config']['xe.user.profileImage.default']);
        $this->setProfileImageResolverOfUser();
        // extend xe auth
        $this->extendAuth();
        // register validation extension for email prefix
        $this->extendValidator();
        // register default user skin
        $this->registerDefaultSkins();
        $this->registerSettingsPermissions();
        // register toggle menu
        $this->registerToggleMenu();
    }