in docs-content/examples-source/material/tabs/tab-group-async/tab-group-async-example.ts [19:29]
constructor() {
this.asyncTabs = new Observable((observer: Observer<ExampleTab[]>) => {
setTimeout(() => {
observer.next([
{label: 'First', content: 'Content 1'},
{label: 'Second', content: 'Content 2'},
{label: 'Third', content: 'Content 3'},
]);
}, 1000);
});
}