public static function email(string $value): bool
    {
        $result = filter_var($value, FILTER_VALIDATE_EMAIL);
        return is_string($result) && $value === $result;
    }
public static function email(string $value): bool
    {
        $result = filter_var($value, FILTER_VALIDATE_EMAIL);
        return is_string($result) && $value === $result;
    }
public static function email ( string $ value ) : bool { $ result = filter_var ( $ value , FILTER_VALIDATE_EMAIL ) ; return is_string ( $ result ) && $ value === $ result ; }
Is email.

@param string $value
@return bool
Is email .