in static/js/bootstrap-tab.js [79:99]
function next() {
$active
.removeClass('active')
.find('> .dropdown-menu > .active')
.removeClass('active')
element.addClass('active')
if (transition) {
element[0].offsetWidth // reflow for transition
element.addClass('in')
} else {
element.removeClass('fade')
}
if ( element.parent('.dropdown-menu') ) {
element.closest('li.dropdown').addClass('active')
}
callback && callback()
}