protected function normaliseSrcInput($input): array
    {
        $output = [];

        if ($input instanceof Finder)
        {
            foreach ($input as $fileInfo)
            {
                $output[] = $fileInfo->getRealpath();
            }
        }
        else
        {
            if (!is_array($input)) $input = [$input];

            if (count($input) === 0) throw new \UnexpectedValueException;

            if (!is_string($input[0])) throw new \UnexpectedValueException;

            $output = $input;
        }

        return $output;
    }