code: protected function basicFetchQuery($context, array $args)
      {
          if ($context !== 'person') {
              throw new \LogicException('TimelineAccompanyingPeriod is not able '
                      . 'to render context '.$context);
          }
          
          $metadata = $this->em
                  ->getClassMetadata('ChillPersonBundle:AccompanyingPeriod')
                  ;
          
          return array(
              'id' => $metadata->getColumnName('id'),
              'date' => $metadata->getColumnName('openingDate'),
              'FROM' => $metadata->getTableName(),
          );
      }
docs: prepare fetchQuery without `WHERE` and `TYPE` clause
  
  @param string $context
  @param array $args
  @return array
  @throws \LogicException