public function testGetOneRandomEntityWithCompositeKey()
 {
     for ($i = 0; $i < 100; $i++) {
         $this->assertNotNull(EntityHelper::getOneRandomEntity($this->em, $this->bookFullClassName));
     }
 }
 protected function getOneRandomEntity($shortEntityName = '')
 {
     if (empty($shortEntityName)) {
         $shortEntityName = self::$shortEntityName;
     }
     return EntityHelper::getOneRandomEntity(static::getEntityManager(), $shortEntityName);
 }