| class A {} | |
| class B extends A {} | |
| class C { | |
| void f1(covariant A x) {} | |
| void f2(A x) {} | |
| void f3(covariant A x) {} | |
| void f4(A x) {} | |
| void f5(covariant A x) {} | |
| void f6(covariant B x) {} | |
| } | |
| class D extends C { | |
| void f1(B x) {} | |
| void f2(covariant B x) {} | |
| void f3(covariant B x) {} | |
| void f4(B x) {} | |
| void f5(covariant String x) {} | |
| void f6(covariant A x) {} | |
| } | |
| main() {} |