private static final int BYTE_MASK = (1 << Byte.SIZE) - 1; // 2^8 - 1 = 255
  private static final int SHORT_MASK = (1 << Short.SIZE) - 1; // 2^16 - 1 = 65_535

  @SuppressWarnings("unchecked")
  static final ImmutableMap<Object, Object> EMPTY =
      new RegularImmutableMap<>(null, new Object[0], 0);

  /*

    bigValues.add(BigInteger.valueOf(Long.MAX_VALUE).add(ONE));
    // Now add values near 2^N for lots of values of N.
    for (int exponent :
        asList(
            64,
            65,
            71,
            72,
            73,
            79,
            80,
            81,
            255,
            256,
            257,
            511,
            512,

        int start = bufferIndex;

        int structureSize = SMBUtil.readInt2(buffer, bufferIndex);
        if ( structureSize != 65 ) {
            throw new SMBProtocolDecodingException("Structure size is not 65");
        }

        this.securityMode = SMBUtil.readInt2(buffer, bufferIndex + 2);
        bufferIndex += 4;

    bigValues.add(BigInteger.valueOf(Long.MAX_VALUE).add(ONE));
    // Now add values near 2^N for lots of values of N.
    for (int exponent :
        asList(
            64,
            65,
            71,
            72,
            73,
            79,
            80,
            81,
            255,
            256,
            257,
            511,
            512,