code: def identifier(self):
          
          ident = self._json['coredata']['dc:identifier'].split(":")[-1]
          if ident != self._id:
              text = "Profile with ID {} has been merged and the new ID is "\
                     "{}.  Please update your records manually.  Files have "\
                     "been cached with the old ID.".format(self._id, ident)
              warn(text, UserWarning)
          return ident
docs: The author's ID.  Might differ from the one provided.