library test /*isNonNullableByDefault*/;
import self as self;
import "dart:core" as core;

abstract class A extends core::Object {
  synthetic constructor •() → self::A
    : super core::Object::•()
    ;
}
abstract class B extends core::Object {
  synthetic constructor •() → self::B
    : super core::Object::•()
    ;
}
class C extends core::Object {
  field self::A a = throw "";
  synthetic constructor •() → self::C
    : super core::Object::•()
    ;
  method f(core::Object o) → void {
    if(o is{ForNonNullableByDefault} self::A || o is{ForNonNullableByDefault} self::B) {
      if(o is{ForNonNullableByDefault} self::A) {
        this.{self::C::a} = o{self::A};
      }
    }
  }
}
static method main() → dynamic {}