Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Helper/Sample.php
public function getFilename($filename, $extension = 'xlsx')
    {
        $originalExtension = pathinfo($filename, PATHINFO_EXTENSION);

        return $this->getTemporaryFolder() . '/' . str_replace('.' . $originalExtension, '.' . $extension, basename($filename));
    }
public function getFilename($filename, $extension = 'xlsx')
    {
        $originalExtension = pathinfo($filename, PATHINFO_EXTENSION);

        return $this->getTemporaryFolder() . '/' . str_replace('.' . $originalExtension, '.' . $extension, basename($filename));
    }
Returns the filename that should be used for sample output.

@param string $filename
@param string $extension

@return string