Interner<Object> interner =
        Interners.newBuilder().weak().concurrencyLevel(concurrencyLevel).build();
    InternerImpl<Object> internerImpl = (InternerImpl<Object>) interner;
    assertEquals(Strength.WEAK, internerImpl.map.keyStrength());
    assertEquals(concurrencyLevel, internerImpl.map.concurrencyLevel);
  }


  public void testWeak_afterGC() throws InterruptedException {
    Integer canonical = new Integer(5);

    Interner<Object> interner =
        Interners.newBuilder().weak().concurrencyLevel(concurrencyLevel).build();
    InternerImpl<Object> internerImpl = (InternerImpl<Object>) interner;
    assertEquals(Strength.WEAK, internerImpl.map.keyStrength());
    assertEquals(concurrencyLevel, internerImpl.map.concurrencyLevel);
  }


  public void testWeak_afterGC() throws InterruptedException {
    Integer canonical = new Integer(5);