}
  }

  public void testRemovalListener_setTwice() {
    RemovalListener<Object, Object> testListener = nullRemovalListener();
    CacheBuilder<Object, Object> builder = CacheBuilder.newBuilder().removalListener(testListener);
    try {
      // even to the same instance is not allowed
      builder = builder.removalListener(testListener);
      fail();
    } catch (IllegalStateException expected) {
    }

    }
  }

  public void testRemovalListener_setTwice() {
    RemovalListener<Object, Object> testListener = nullRemovalListener();
    CacheBuilder<Object, Object> builder = CacheBuilder.newBuilder().removalListener(testListener);
    try {
      // even to the same instance is not allowed
      builder = builder.removalListener(testListener);
      fail();
    } catch (IllegalStateException expected) {
    }

        boolean accessOrder,
        long maximumSize,
        StatsCounter statsCounter,
        @Nullable RemovalListener<? super K, ? super V> removalListener) {
      super(initialCapacity, loadFactor, accessOrder);
      this.maximumSize = maximumSize;
      this.statsCounter = statsCounter;
      this.removalListener = removalListener;
    }

    @Override
    protected boolean removeEldestEntry(Entry<K, Timestamped<V>> ignored) {

   */
  public <K1 extends K, V1 extends V> CacheBuilder<K1, V1> removalListener(
      RemovalListener<? super K1, ? super V1> listener) {
    checkState(this.removalListener == null);

    // safely limiting the kinds of caches this can produce
    @SuppressWarnings("unchecked")
    CacheBuilder<K1, V1> me = (CacheBuilder<K1, V1>) this;
    me.removalListener = checkNotNull(listener);
    return me;
  }

    assertEquals("keyEquivalence", a.keyEquivalence, b.keyEquivalence);
    assertEquals("keyStrength", a.keyStrength, b.keyStrength);
    assertEquals("removalListener", a.removalListener, b.removalListener);
    assertEquals("weigher", a.weigher, b.weigher);
    assertEquals("valueEquivalence", a.valueEquivalence, b.valueEquivalence);
    assertEquals("valueStrength", a.valueStrength, b.valueStrength);

    assertEquals("keyEquivalence", a.keyEquivalence, b.keyEquivalence);
    assertEquals("keyStrength", a.keyStrength, b.keyStrength);
    assertEquals("removalListener", a.removalListener, b.removalListener);
    assertEquals("weigher", a.weigher, b.weigher);
    assertEquals("valueEquivalence", a.valueEquivalence, b.valueEquivalence);
    assertEquals("valueStrength", a.valueStrength, b.valueStrength);