protected function processAll($filepath, $preview = false)
 {
     //configre a CsvBulkLoaderSource
     $source = new CsvBulkLoaderSource();
     $source->setFilePath($filepath);
     $source->setHasHeader($this->hasHeaderRow);
     $source->setFieldDelimiter($this->delimiter);
     $source->setFieldEnclosure($this->enclosure);
     $this->setSource($source);
     return parent::processAll($filepath, $preview);
 }