code: public function get(string $key)
      {
          Validation::validateKey($key);
  
          // Fetch the key from cache
          if ($cache = $this->getConfig()->getCache()) {
              if ($cache->contains($key)) {
                  return $cache->get($key);
              }
          }
  
          // Fetch the key from database
          $file = $this->getDatabase()->readFromFile();
          $data = false;
  
          foreach ($file as $line) {
              /** @var Line $line */
              if ($line->getKey() == $key) {
                  $data = $this->decodeData($line->getData());
                  break;
              }
          }
  
          // Save the data to cache
          if ($cache && $data !== false) {
              $cache->set($key, $data);
          }
  
          return $data;
      }
docs: Get a key from the database.
  
  @param string $key
  
  @return mixed