/** Number of bytes to be filled before process() invocation(s). */
  private final int bufferSize;

  /** Number of bytes processed per process() invocation. */
  private final int chunkSize;

  /**
   * Constructor for use by subclasses. This hasher instance will process chunks of the specified
   * size.
   *
   * @param chunkSize the number of bytes available per {@link #process(ByteBuffer)} invocation;
   *     must be at least 4