in Dataset/JS/AngularCalendar/calendarDemo.js [60:71]
$scope.addRemoveEventSource = function(sources,source) {
var canAdd = 0;
angular.forEach(sources,function(value, key){
if(sources[key] === source){
sources.splice(key,1);
canAdd = 1;
}
});
if(canAdd === 0){
sources.push(source);
}
};