ByteVector put12(final int b, final int s) {
        int length = this.length;
        if (length + 3 > data.length) {
            enlarge(3);
        }
        byte[] data = this.data;
        data[length++] = (byte) b;
        data[length++] = (byte) (s >>> 8);
        data[length++] = (byte) s;
        this.length = length;
        return this;
    }