code: public function getCfg($path = null)
      {
          if (!\strlen($path)) {
              return $this->cfg;
          }
          if (isset($this->cfg[$path])) {
              return $this->cfg[$path];
          }
          return null;
      }
docs: Retrieve a config or data value
  
  @param string $path what to get
  
  @return mixed