checker/tests/mustcall/MapWrap.java

// A test for a class that wraps a map. I found a similar example in Zookeeper that causes false
// positives.

import java.util.HashMap;
import org.checkerframework.checker.mustcall.qual.*;

class MapWrap<E> {
  HashMap<E, String> impl = new HashMap<E, String>();

  String remove(E e) {
    // remove should permit any object: its signature is remove(Object key), *not* remove(E key)
    String old = impl.remove(e);
    return old;
  }

  String remove2(@MustCall({}) E e) {
    // remove should permit any object: its signature is remove(Object key), *not* remove(E key)
    String old = impl.remove(e);
    return old;
  }
}