public function get($key, $defaultOverride = NULL) {
    $value = parent::get($key, $defaultOverride);

    // Last ditch effort to expand properties that may not have been processed.
    if (is_string($value) && strstr($value, '$')) {
      $expanded = Expander::expandArrayProperties([$value], $this->export());
      $value = $expanded[0];
    }

    return $value;
  }