return;
    }

    Set<K> keys = map.keySet();
    K key = keys.iterator().next();
    if (supportsRemove) {
      int initialSize = map.size();
      keys.remove(key);
      assertEquals(initialSize - 1, map.size());
      assertFalse(map.containsKey(key));
    } else {
      assertThrows(UnsupportedOperationException.class, () -> keys.remove(key));
    }
    assertInvariants(map);
  }

  }

  abstract Set<K> createKeySet();

  @LazyInit private transient @Nullable Multiset<K> keys;

  @Override
  public Multiset<K> keys() {
    Multiset<K> result = keys;
    return (result == null) ? keys = createKeys() : result;
  }

  abstract Multiset<K> createKeys();

  @LazyInit private transient @Nullable Collection<V> values;

  @Override

    @Test
    @DisplayName("Should accept empty keys")
    void testEmptyKeys() {
        // Given
        byte[] emptyKey = new byte[0];

        // When/Then
        assertDoesNotThrow(() -> {
            Smb2EncryptionContext context = new Smb2EncryptionContext(1, DialectVersion.SMB311, emptyKey, emptyKey);
            assertNotNull(context, "Context should be created with empty keys");
        }, "Should accept empty keys");
    }

	//   error: An error if the statement preparation fails.
	New(ctx context.Context, key string, isTransaction bool, connPool ConnPool, locker sync.Locker) (*Stmt, error)

	// Keys returns a slice of all cache keys in the store.
	Keys() []string

	// Get retrieves a Stmt object from the store based on the given key.
	// Parameters:
	//   key: The key used to look up the Stmt object.
	// Returns:

   * equal.
   */
  boolean areEqual();

  /**
   * Returns an unmodifiable map containing the entries from the left map whose keys are not present
   * in the right map.
   */
  Map<K, V> entriesOnlyOnLeft();

  /**
   * Returns an unmodifiable map containing the entries from the right map whose keys are not
   * present in the left map.
   */
  Map<K, V> entriesOnlyOnRight();

  /**

apt-get update
apt-get install -y gnupg ca-certificates

# Deadsnakes: https://launchpad.net/~deadsnakes/+archive/ubuntu/ppa
apt-key adv --keyserver keyserver.ubuntu.com --recv-keys F23C5A6CF475977595C89F51BA6932366A755776

# LLVM/Clang: https://apt.llvm.org/
apt-key adv --fetch-keys https://apt.llvm.org/llvm-snapshot.gpg.key

# Set up custom sources
cat >/etc/apt/sources.list.d/custom.list <<SOURCES
# More Python versions: Deadsnakes

 * interface. It does not permit null keys or values.
 *
 * <p><b>Note:</b> by default, the returned map uses equality comparisons (the {@link Object#equals
 * equals} method) to determine equality for keys or values. However, if {@link #weakKeys} was
 * specified, the map uses identity ({@code ==}) comparisons instead for keys. Likewise, if {@link

   * numbers of keys and values without resizing.
   *
   * <p>You may also consider the equivalent {@code
   * MultimapBuilder.hashKeys(expectedKeys).arrayListValues(expectedValuesPerKey).build()}, which
   * provides more control over the underlying data structure.
   *
   * @param expectedKeys the expected number of distinct keys

    assertThat(map.needsAllocArrays()).isTrue();
    assertThat(map.entries).isNull();
    assertThat(map.keys).isNull();
    assertThat(map.values).isNull();

    map.put(1, "1");
    assertThat(map.needsAllocArrays()).isFalse();
    assertThat(map.entries).hasLength(CompactHashing.DEFAULT_SIZE);
    assertThat(map.keys).hasLength(CompactHashing.DEFAULT_SIZE);
    assertThat(map.values).hasLength(CompactHashing.DEFAULT_SIZE);
  }

  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testPutPresentKeyPropagatesToGet() {
    List<K> keys = copyToList(multimap().keySet());
    for (K key : keys) {
      resetContainer();

      int size = getNumElements();

      Collection<V> collection = multimap().get(key);
      Collection<V> expectedCollection = copyToList(collection);