/**
  * @param mixed $date
  * @return string
  */
 protected function toString($date)
 {
     if (!$date instanceof \DateTime) {
         return '';
     }
     return $this->dateTimeService->getDateStringFromDateTime($date);
 }
 /**
  * @test
  * @dataProvider dateTimeTestCaseDataProvider
  */
 public function canConvertToDateTimeObject($stringDateTime, $dateTime)
 {
     $this->assertEquals($dateTime, $this->dateTimeService->getDateTimeFromApiDateString($stringDateTime));
 }