title: Angular 5 component test get debugElement by ID
body: <p>I have a component containing 3 select dropdowns with no css classes attached and a unique Id on each.  In my component I want to get the elements as DebugElements so that I can test their states after various events have been triggered.  From the Angular website there is <code>debugElement.query(By.css('[attribute]'));</code>.  How can I get my dropdowns By.id</p>