| // Copyright (c) 2023, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| class A {} |
| extension type E(Object? it) {} |
| typedef TA = A; |
| typedef TE = E; |
| |
| extension type E1(A it) implements A, A {} // Error. |
| |
| extension type E2(E it) implements E, E {} // Error. |
| |
| extension type E3(A it) implements A, TA, A, TA {} // Error. |
| |
| extension type E4(E it) implements E, TE, E, TE {} // Error. |
