code: protected function &searchNode(
          /*# string */ $path,
          array &$data,
          /*# bool */ $create = true
      ) {
          $found = &$data;
          foreach (explode($this->splitter, $path) as $k) {
              $found = &$this->childNode($k, $found, $create);
              if (null === $found) {
                  break;
              }
          }
          return $found;
      }
docs: Search a node in the $data
  
  @param  string $path
  @param  array &$data
  @param  bool $create
  @return mixed null for not found
  @access protected
  @since  2.0.6 bug fix