pkg/front_end/testcases/extensions/issue39527.dart.textual_outline.expect

// @dart = 2.9
class C {
  int value = 0;
}

extension Extension1 on C {
  C operator [](int index) => this..value += index + 1;
  void operator []=(int index, C other) =>
      this.value += other.value + index + 1;
  C operator -(int val) => this;
}

main() {}