code: public function get($keys, $default = null)
      {
          $result = $this->data;
          foreach (is_array($keys) ? $keys : [$keys] as $key) {
              if (is_array($result) && isset($result[$key])) {
                  $result = $result[$key];
              } else {
                  $result = $default;
                  break;
              }
          }
          return $result;
      }
docs: Returns a value from the data container.
  @param string|string[]
  @param mixed $default
  @return mixed