// @dart = 2.9 | |
class A { | |
void foo() {} | |
} | |
abstract class I { | |
void foo([a]); | |
} | |
abstract class B extends A { | |
void foo([a]); | |
} | |
class C extends B {} | |
class D extends A implements I {} | |
abstract class E extends A implements I {} | |
class F extends E {} | |
main() {} |