MessagePack\BufferUnpacker::unpackInt8 PHP Method

    private function unpackInt8()
    {
        if (!isset($this->buffer[$this->offset])) {
            throw new InsufficientDataException(1, \strlen($this->buffer) - $this->offset);
        }
        $num = \ord($this->buffer[$this->offset]);
        ++$this->offset;
        if ($num > 0x7f) {
            return $num - 256;
        }
        return $num;
    }