Chapter-10 Debugelement & DOM events

Debugelement is an interface created to work safely across different platforms.
Debugelement creates DebugElement tree that wraps the native elements for platforms, instead of HTML element tree.
The DebugElement associated with the root element of the component.
Debugelement comes with methods and properties that are useful for testing.
nativeElement property returns us platform specific object.
triggerEventHandler will help us to execute the DOM events