import java.util.Map;
import org.checkerframework.checker.nullness.qual.EnsuresKeyFor;

public class EnsuresKeyForOverriding {
  static class MyClass {
    Object field = new Object();
  }

  MyClass o = new MyClass();

  @EnsuresKeyFor(value = "#1.field", map = "#2")
  void method(MyClass o, Map<Object, Object> map) {
    map.put(o.field, "Hello");
  }

  static class SubEnsuresKeyForOverriding extends EnsuresKeyForOverriding {
    @Override
    @EnsuresKeyFor(value = "#1.field", map = "#2")
    void method(MyClass q, Map<Object, Object> subMap) {
      super.method(q, subMap);
    }
  }
}