public function testTsvAction()
 {
     $data = [['id' => '1', 'name' => 'ciao', 'a' => 'mondo'], ['id' => '2', 'name' => 'hello', 'a' => 'world']];
     $writer = new TSV();
     $writer->openURI('tsv.tsv');
     echo $writer->beginOutput();
     foreach ($data as $doc) {
         echo $writer->addDocument($doc);
         sleep(5);
     }
     echo $writer->endOutput();
 }
 /**
  * {@inheritdoc}
  */
 public static function tearDownAfterClass()
 {
     if (static::$write) {
         self::$writer->endOutput();
     }
 }