Number of todos
Implementation
ng-class="todo.completed && 'success'"
ng-class="{success: todo.completed}"
ng-class="{completed: todo.completed, urgent: todo.urgent, important: todo.important"}
ng-class="{'panel-success': !!benchmark.todos, 'panel-danger': !benchmark.todos}"
ng-class="{'panel-success': benchmark.todos, 'panel-danger': !benchmark.todos}"