runtimeType behaviour

runtimeType.dart

void main() {  
  String s = "Dart";
  print(s is String);        // true
  print(s.runtimeType);      // String
  
  Dart d = new Dart();
  NotDart nd = new NotDart();
  print(d is Dart);          // true
  print(nd is Dart);         // false
  print(nd is NotDart);      // true
  print(nd.runtimeType);     // Dart
  print(d.runtimeType == nd.runtimeType); // true
}

class Dart {}

class NotDart {
  Type get runtimeType => Dart;
}