code: def undelete(self, original_filepath):
          
          candidates = self.versions(original_filepath)
          if not candidates:
              raise x_not_found_in_recycle_bin("%s not found in the Recycle Bin" % original_filepath)
          #
          # NB Can't use max(key=...) until Python 2.6+
          #
          newest = sorted(candidates, key=lambda entry: entry.recycle_date())[-1]
          return newest.undelete()
docs: Restore the most recent version of a filepath, returning
          the filepath it was restored to(as rename-on-collision will
          apply if a file already exists at that path).