checker/tests/nullness/Issue961.java

import java.util.HashMap;
import java.util.Map;
import org.checkerframework.checker.nullness.qual.NonNull;

// Test case for Issue 961
// https://github.com/typetools/checker-framework/issues/961
public class Issue961 {
  <T extends @NonNull Object> T method(T param, Map<T, Object> map) {
    if (map.containsKey(param)) {
      @NonNull Object o = map.get(param);
      return param;
    }
    return param;
  }

  abstract class MapContains<K extends @NonNull Object, V extends @NonNull Object> {
    // this isn't initialized, but just ignore the error.
    @SuppressWarnings("method.invocation")
    V def = setDef();

    Map<K, V> map = new HashMap<>();

    V get(K p) {
      if (!map.containsKey(p)) {
        return def;
      }
      return map.get(p);
    }

    abstract V setDef();
  }

  class MapContains2 {
    String get1(Map<Object, String> map, Object k) {
      if (!map.containsKey(k)) {
        return "";
      }
      return map.get(k);
    }

    <KeyTV extends @NonNull Object> String get2(Map<Object, String> map, KeyTV k) {
      if (!map.containsKey(k)) {
        return "";
      }
      return map.get(k);
    }
  }
}