keys.remove(1);
      keys.remove(2);
      assertFalse(keys.remove(null));
      assertFalse(keys.remove(6));
      assertFalse(keys.remove(-6));
      assertFalse(keys.removeAll(asList(null, 0, 15, 1500)));
      assertFalse(keys.retainAll(asList(null, 0, 15, 1500)));
      checkEmpty(keys);
      checkEmpty(cache);
    }
  }

  }

  /**
   * Associates the value {@code null} with the specified keys, assuming both keys are valid. If
   * either key is null or isn't among the keys provided during construction, this method has no
   * effect.
   *
   * <p>This method is equivalent to {@code put(rowKey, columnKey, null)} when both provided keys
   * are valid.
   *
   * @param rowKey row key of mapping to be erased

    private final ImmutableList<String> keys;
    private final Random random = new Random();

    private MutateTask(ConcurrentHashMultiset<String> multiset, ImmutableList<String> keys) {
      this.multiset = multiset;
      this.keys = keys;
    }

    @Override
    public int[] call() throws Exception {
      int iterations = 100000;
      int nKeys = keys.size();
      int[] deltas = new int[nKeys];

        secureRandom.nextBytes(key);
        return key;
    }

    /**
     * Clear all stored keys
     */
    public void clearAllKeys() {
        checkNotClosed();

        log.info("Clearing all stored keys");

        // Wipe all raw keys
        for (Map.Entry<String, byte[]> entry : rawKeys.entrySet()) {
            Arrays.fill(entry.getValue(), (byte) 0);
        }

class PacTest {

    private Map<Integer, KerberosKey> keys;

    @BeforeEach
    void setUp() {
        keys = new HashMap<>();
        // Use ARCFOUR-HMAC encryption type (23) which matches KERB_CHECKSUM_HMAC_MD5
        KerberosKey serverKey = new KerberosKey(new KerberosPrincipal("******@****.***"), "serverKey1234567".getBytes(),
                PacSignature.ETYPE_ARCFOUR_HMAC, 1);
        keys.put(PacSignature.ETYPE_ARCFOUR_HMAC, serverKey);
    }

  /**
   * Associates the specified value with the specified keys. If the table already contained a
   * mapping for those keys, the old value is replaced with the specified value.
   *
   * @param rowKey row key that the value should be associated with
   * @param columnKey column key that the value should be associated with
   * @param value value to be associated with the specified keys

    return linkedHashKeys(DEFAULT_EXPECTED_KEYS);
  }

  /**
   * Uses an hash table to map keys to value collections, initialized to expect the specified number
   * of keys.
   *
   * <p>The collections returned by {@link Multimap#keySet()}, {@link Multimap#keys()}, and {@link
   * Multimap#asMap()} will iterate through the keys in the order that they were first added to the

    return linkedHashKeys(DEFAULT_EXPECTED_KEYS);
  }

  /**
   * Uses an hash table to map keys to value collections, initialized to expect the specified number
   * of keys.
   *
   * <p>The collections returned by {@link Multimap#keySet()}, {@link Multimap#keys()}, and {@link
   * Multimap#asMap()} will iterate through the keys in the order that they were first added to the

          .addEqualityGroup(cache.asMap().keySet(), keys)
          .addEqualityGroup(ImmutableSet.of())
          .testEquals();
      assertEquals(WARMUP_SIZE, keys.size());
      for (int i = WARMUP_MIN; i < WARMUP_MAX; i++) {
        Object key = warmed.get(i - WARMUP_MIN).getKey();
        assertTrue(keys.contains(key));
        assertTrue(keys.remove(key));
        assertFalse(keys.remove(key));
        assertFalse(keys.contains(key));

  /**
   * Returns a {@link Collector} that accumulates elements into an {@code ImmutableBiMap} whose keys
   * and values are the result of applying the provided mapping functions to the input elements.
   * Entries appear in the result {@code ImmutableBiMap} in encounter order.
   *
   * <p>If the mapped keys or values contain duplicates (according to {@link