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);
    }
  }

        return ImmutableMultiset.copyOf(keys);
      }
    },
    COPY_OF_ITERATOR {
      @Override
      public ImmutableMultiset<Object> create(List<?> keys) {
        return ImmutableMultiset.copyOf(keys.iterator());
      }
    },
    BUILDER_ADD_ENTRY_BY_ENTRY {
      @Override
      public ImmutableMultiset<Object> create(List<?> keys) {

  }

  /**
   * 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

// Batch represents an ordered batch
type Batch[K key, T any] struct {
	keys  []K
	items map[K]T
	limit uint32

	sync.Mutex
}

// Add adds the item to the batch
func (b *Batch[K, T]) Add(key K, item T) error {
	b.Lock()
	defer b.Unlock()

	if b.isFull() {
		return ErrBatchFull
	}

	if _, ok := b.items[key]; !ok {
		b.keys = append(b.keys, key)
	}
	b.items[key] = item

	return nil
}

        DocMap docMap = new DocMap(value);
        assertTrue(docMap.isEmpty());
        value.clear();

        List<String> keys = Arrays.asList("test_2", "test_0", "lang", "test_1");
        value.put(keys.get(0), true);
        value.put(keys.get(1), 1000);
        value.put(keys.get(2), "ja");
        value.put(keys.get(3), "str");
        docMap = new DocMap(value);
        assertFalse(docMap.isEmpty());

	}
	keys, items, err := batch.GetAll()
	if err != nil {
		t.Fatalf("unable to get the items from the batch; %v", err)
	}
	if len(items) != int(limit) {
		t.Fatalf("Expected length of the batch items to be %v but got %v", limit, len(items))
	}
	if len(keys) != int(limit) {
		t.Fatalf("Expected length of the batch keys to be %v but got %v", limit, len(items))
	}
	batchLen = batch.Len()

    this.keys = keys;
    this.values = values;
  }

  @Override
  public SampleElements<Entry<K, V>> samples() {
    return SampleElements.mapEntries(keys, values);
  }

  @Override
  public Set<Entry<K, V>> create(Object... elements) {
    Entry<K, V>[] entries = createArray(elements.length);
    System.arraycopy(elements, 0, entries, 0, elements.length);

  /**
   * 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

                        keys ->
                            path.create(
                                Lists.transform(
                                    keys, key -> Maps.immutableEntry(key, new Object()))),
                        keys ->
                            path.create(
                                Lists.transform(
                                    keys, key -> Maps.immutableEntry(new Object(), key))),

	}
	return v
}

// Keys returns the list of keys for the current KVS
func (kvs KVS) Keys() []string {
	keys := make([]string, len(kvs))
	var foundComment bool
	for i := range kvs {
		if kvs[i].Key == madmin.CommentKey {
			foundComment = true
		}
		keys[i] = kvs[i].Key
	}
	// Comment KV not found, add it explicitly.
	if !foundComment {
		keys = append(keys, madmin.CommentKey)
	}
	return keys