@Override
          public @Nullable Object getIfPresent(Object key) {
            return null;
          }
        };

    assertEquals(ImmutableMap.of(), cache.getAllPresent(ImmutableList.of(new Object())));
  }

  public void testGetAllPresent_cached() {
    Object cachedKey = new Object();
    Object cachedValue = new Object();
    Cache<Object, Object> cache =

  /*
   * <? extends Object> is mostly the same as <?> to plain Java. But to nullness checkers, they
   * differ: <? extends Object> means "non-null types," while <?> means "all types."
   */
  ImmutableMap<K, V> getAllPresent(Iterable<? extends Object> keys);

  /**
   * Associates {@code value} with {@code key} in this cache. If the cache previously contained a
   * value associated with {@code key}, the old value is replaced by {@code value}.

  /*
   * <? extends Object> is mostly the same as <?> to plain Java. But to nullness checkers, they
   * differ: <? extends Object> means "non-null types," while <?> means "all types."
   */
  ImmutableMap<K, V> getAllPresent(Iterable<? extends Object> keys);

  /**
   * Associates {@code value} with {@code key} in this cache. If the cache previously contained a
   * value associated with {@code key}, the old value is replaced by {@code value}.