code: protected function randomizeSamples($referencePrefix, array $samples, $limit = 1)
      {
          $sample = array_rand($samples, $limit);
          
          if (1 === $limit) {
              $referenceName = sprintf('%s_%s', $referencePrefix, $samples[$sample]);
              
              return $this->getReference($referenceName);
          } else {
              $collection = new ArrayCollection();
              foreach ($sample as $index) {
                  $referenceName = sprintf('%s_%s', $referencePrefix, $samples[$index]);
                  $collection->add($this->getReference($referenceName));
              }
              
              return $collection;
          }
      }
docs: Returns random entity or collection of entities
  
  @param       $referencePrefix
  @param array $samples
  @param int   $limit
  
  @return object