private static function costHash(string $cost, string $pass): string
    {
        return Str::substr(\hash_hmac(self::ALGO, $cost, $pass, true), 0, 8);
    }
private static function costHash(string $cost, string $pass): string
    {
        return Str::substr(\hash_hmac(self::ALGO, $cost, $pass, true), 0, 8);
    }
private static function costHash ( string $ cost , string $ pass ) : string { return Str :: substr ( \ hash_hmac ( self :: ALGO , $ cost , $ pass , true ) , 0 , 8 ) ; }
Returns the correct hash for an encrypted cost value.

@param string $cost
@param string $pass
@return string
Returns the correct hash for an encrypted cost value .