.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));

    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];

    int[] entries = requireEntries();
    @Nullable Object[] keys = requireKeys();
    @Nullable Object[] values = requireValues();
    int srcIndex = size() - 1;
    if (dstIndex < srcIndex) {
      // move last entry to deleted spot
      Object key = keys[srcIndex];
      keys[dstIndex] = key;
      values[dstIndex] = values[srcIndex];
      keys[srcIndex] = null;
      values[srcIndex] = null;

    }

    @SuppressWarnings("unchecked")
    final Object legacyReadResolve() {
      K[] keys = (K[]) this.keys;
      V[] values = (V[]) this.values;

      Builder<K, V> builder = makeBuilder(keys.length);

      for (int i = 0; i < keys.length; i++) {
        builder.put(keys[i], values[i]);
      }
      return builder.buildOrThrow();
    }

    /**

        CurlRequest result = request.param("key1", "value1").param("key2", "value2");

        assertSame(request, result); // Fluent API
    }

    @Test
    public void testParamWithNullValue() {
        CurlRequest request = new CurlRequest(Method.GET, "https://example.com");

        CurlRequest result = request.param("key", null);

  Multiset<K> createKeys() {
    return new Keys();
  }

  @WeakOuter
  final class Keys extends Multimaps.Keys<K, V> {
    Keys() {
      super(FilteredEntryMultimap.this);
    }

    @Override
    public int remove(@Nullable Object key, int occurrences) {
      checkNonnegative(occurrences, "occurrences");
      if (occurrences == 0) {
        return count(key);
      }

  /** Discards any cached value for key {@code key}. */
  void invalidate(@CompatibleWith("K") Object key);

  /**
   * Discards any cached values for keys {@code keys}.
   *
   * @since 11.0
   */
  // For discussion of <? extends Object>, see getAllPresent.
  void invalidateAll(Iterable<? extends Object> keys);

  /** Discards all entries in the cache. */
  void invalidateAll();

   *     multimap already contained the key-value pair and doesn't allow duplicates
   */
  @CanIgnoreReturnValue
  boolean put(@ParametricNullness K key, @ParametricNullness V value);

  /**
   * Removes a single key-value pair with the key {@code key} and the value {@code value} from this
   * multimap, if such exists. If multiple key-value pairs in the multimap fit this description,
   * which one is removed is unspecified.
   *

      }
    }

    @Override
    public boolean containsKey(@Nullable Object key) {
      return rangeContains(key) && super.containsKey(key);
    }

    @Override
    public @Nullable V put(C key, V value) {
      checkArgument(rangeContains(checkNotNull(key)));
      return super.put(key, value);
    }
  }

  }

  /**
   * Uses a hash table to map keys to value collections.
   *
   * <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
   * multimap, save that if all values associated with a key are removed and then the key is added
   * back into the multimap, that key will come last in the key iteration order.
   */