class Class<X5 extends X4, X4 extends X3, X3 extends X2, X2 extends X1,
    X1 extends X0, X0 extends int> {
  X0 field0;
  X1 field1;
  X2 field2;
  X3 field3;
  X4 field4;
  X5 field5;
  method() {}
}

class DynamicClass<T extends dynamic, S extends T> {
  DynamicClass(this.field1, this.field2);
  T field1;
  T field2;
  method() => field1 * field2;
}

class NumClass<T extends num, S extends T> {
  NumClass(this.field1, this.field2);
  S field2;
  T field1;
  num method1() => field1 * field2;
  num method2() => field1 + field2.length;
}

main() {}