}

  public void testEviction_maxSize() {
    CountingRemovalListener<Integer, Integer> removalListener = countingRemovalListener();
    IdentityLoader<Integer> loader = identityLoader();
    LoadingCache<Integer, Integer> cache =
        CacheBuilder.newBuilder()
            .maximumSize(MAX_SIZE)
            .removalListener(removalListener)
            .build(loader);
    for (int i = 0; i < 2 * MAX_SIZE; i++) {

   */
  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;
  }

  }

  public void testRemovalListener_setTwice() {
    RemovalListener<Object, Object> testListener = nullRemovalListener();
    CacheBuilder<Object, Object> builder = CacheBuilder.newBuilder().removalListener(testListener);
    assertThrows(IllegalStateException.class, () -> builder.removalListener(testListener));
  }

  public void testValuesIsNotASet() {

  }

  public void testRemovalListener_setTwice() {
    RemovalListener<Object, Object> testListener = nullRemovalListener();
    CacheBuilder<Object, Object> builder = CacheBuilder.newBuilder().removalListener(testListener);
    assertThrows(IllegalStateException.class, () -> builder.removalListener(testListener));
  }

  public void testValuesIsNotASet() {

    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(Integer.valueOf(50), asMap.get(10));
  }

  public void testRemovalListener() {
    int[] stats = new int[4];

    RemovalListener<Integer, Integer> countingListener =
        new RemovalListener<Integer, Integer>() {
          @Override
          public void onRemoval(RemovalNotification<Integer, Integer> notification) {
            switch (notification.getCause()) {

    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);

            }
            return key.toString();
          }
        };
    CountingRemovalListener<Integer, String> removalListener = countingRemovalListener();
    LoadingCache<Integer, String> cache =
        CacheBuilder.newBuilder().removalListener(removalListener).build(failOnceFunction);

    UncheckedExecutionException ue =

            listeners.add(listener);
        }
    }

    /**
     * Remove a listener
     *
     * @param listener the listener to remove
     */
    public void removeListener(CircuitBreakerListener listener) {
        listeners.remove(listener);
    }

    /**
     * Get circuit breaker metrics
     *
     * @return metrics snapshot
     */