protected function createRootFolder()
    {
        $this->rootFolder = $this->createFolder($this->baseFolderRealPath, uniqid('xlsx', true));
        return $this;
    }
protected function createRootFolder()
    {
        $this->rootFolder = $this->createFolder($this->baseFolderRealPath, uniqid('xlsx', true));
        return $this;
    }
protected function createRootFolder ( ) { $ this -> rootFolder = $ this -> createFolder ( $ this -> baseFolderRealPath , uniqid ( 'xlsx' , true ) ) ; return $ this ; }
Creates the folder that will be used as root

@return FileSystemHelper
@throws \Box\Spout\Common\Exception\IOException If unable to create the folder
Creates the folder that will be used as root