code: protected function saveToCache()
      {
          // Pretty print only came available with php 5.4.
          $flags = 0;
          if (defined('JSON_PRETTY_PRINT')) {
              $flags = JSON_PRETTY_PRINT;
          }
  
          return $this->container->getCache()->save(
              $this->calculateCacheKey(),
              json_encode(
                  array(
                      'information' => $this->information,
                      'tableMap'    => $this->tableMap,
                      'parentMap'   => $this->parentMap,
                      'childMap'    => $this->childMap
                  ),
                  $flags
              )
          );
      }
docs: Try to load the combinations from cache.
  
  @return bool