private final int timestamp;

  private final long nonce;
  
  public FastObjectId(final byte[] bytes) {
    this(
        ByteBuffer.wrap(
            isTrueArgument("bytes has length of 12", bytes, notNull("bytes", bytes).length == 12)));
  }


  public FastObjectId(final ByteBuffer buffer) {
    notNull("buffer", buffer);
    isTrueArgument("buffer.remaining() >=12", buffer.remaining() >= OBJECT_ID_LENGTH);
    ByteOrder originalOrder = buffer.order();
    buffer.order(ByteOrder.BIG_ENDIAN);
    timestamp = buffer.getInt();
    nonce = buffer.getLong();
    buffer.order(originalOrder);
  }


  public byte[] toByteArray() {
    return ByteBuffer.allocate(OBJECT_ID_LENGTH)
        .putInt(timestamp) 
        .putLong(nonce)
        .array();
  }


  public void putToByteBuffer(final ByteBuffer buffer) {
    notNull("buffer", buffer);
    isTrueArgument("buffer.remaining() >=12", buffer.remaining() >= OBJECT_ID_LENGTH);

    ByteOrder original = buffer.order();
    buffer.order(ByteOrder.BIG_ENDIAN)
        .putInt(timestamp)
        .putLong(nonce)
        .order(original);
  }

  @Override
  public boolean equals(final Object o) {
    if (this == o) {
      return true;
    }
    if (o == null || getClass() != o.getClass()) {
      return false;
    }

    FastObjectId other = (FastObjectId) o;
    if (nonce != other.nonce) {
      return false;
    }
    return timestamp == other.timestamp;
  }

  @Override
  public int hashCode() {
    return 31 * timestamp + Long.hashCode(nonce);
  }

  @Override
  public int compareTo(final BaseObjectId other) {
    if (other == null) {
      throw new NullPointerException();
    }

    int cmp = Integer.compareUnsigned(this.timestamp, other.timestamp);
    if (cmp != 0) {
      return cmp;
    }

    return Long.compareUnsigned(nonce, other.nonce);
  }