        let max = availableIconLibraries.length;
                let randomIndex = Math.floor(Math.random() * max);

                // set a random library
                let currentIconLibrary = availableIconLibraries[randomIndex].iconLibrary,
                    currentIconLibraryCss = availableIconLibraries[randomIndex].iconLibraryCss;
                uip.setOptions({
                    iconLibraries: [currentIconLibrary + '.min.json'],
                    iconLibrariesCss: [currentIconLibraryCss]
   