protected static function _dump($string)
{
$es = ['0', 'x07', 'x08', 't', 'n', 'v', 'f', 'r'];
$unescaped = '';
$chars = str_split($string);
foreach ($chars as $char) {
if ($char === '') {
continue;
}
$value = ord($char);
if ($value >= 7 && $value <= 13) {
$unescaped .= '\\' . $es[$value - 6];
} elseif ($char === '"' || $char === '$' || $char === '\\') {
$unescaped .= '\\' . $char;
} else {
$unescaped .= $char;
}
}
return $unescaped;
}