public function __construct(array $config){
$this->_expected = (string)$config['expected'];
$this->_actual = (string)$config['actual'];
$message = sprintf(
'%s %s %s %s %s',
(string)($this->_actual - $this->_expected),
' extra bytes before header. Expected pos ',
$this->_expected,
' but found the header at ',
$this->_actual
);
parent::__construct($message);
}