message: Avoid a redundant duplicate get_aref()
  Summary: Probably not measurable, but cleaner.
diff: @@ -444,7 +444,7 @@ impl<'v> Value<'v> {
  /// `dir()` function.
  pub fn dir_attr(self) -> Vec<String> {
  let aref = self.get_aref();
  - let mut result = if let Some(methods) = self.get_aref().get_methods() {
  + let mut result = if let Some(methods) = aref.get_methods() {
  let mut res = methods.names();
  res.extend(aref.dir_attr());
  res
  