final public static function className(string $fullName = null): string
    {
        $fullName = $fullName ?: self::fullName();
        $fullName = str_replace('\\', '/', $fullName);

        return basename($fullName);
    }
final public static function className(string $fullName = null): string
    {
        $fullName = $fullName ?: self::fullName();
        $fullName = str_replace('\\', '/', $fullName);

        return basename($fullName);
    }
final public static function className ( string $ fullName = null ) : string { $ fullName = $ fullName ? : self :: fullName ( ) ; $ fullName = str_replace ( '\\' , '/' , $ fullName ) ; return basename ( $ fullName ) ; }
get called class name
@param null|string $fullName
@return string
get called class name