private function _returnHash(string $hash, int $length)
    {
        try {
            return substr($hash, 0, $length);
        } catch (\Exception $e) { }

        return false;
    }
private function _returnHash(string $hash, int $length)
    {
        try {
            return substr($hash, 0, $length);
        } catch (\Exception $e) { }

        return false;
    }
private function _returnHash ( string $ hash , int $ length ) { try { return substr ( $ hash , 0 , $ length ) ; } catch ( \ Exception $ e ) { } return false ; }
Hashes a string

@param string $hash   The string to hash
@param int    $length The length of the hash

@return string
Hashes a string