docs: def rename_user(self, old_user, new_user):
          """Rename a JIRA user.
  
          :param old_user: Old username login
          :type old_user: str
          :param new_user: New username login
          :type new_user: str
  
          """
          if self._version > (6, 0, 0):
              url = self._options['server'] + '/rest/api/latest/user'
              payload = {
                  "name": new_user}
              params = {
                  'username': old_user}
  
              # raw displayName
              logging.debug("renaming %s" % self.user(old_user).emailAddress)
  
              r = self._session.put(url, params=params,
                                    data=json.dumps(payload))
              raise_on_error(r)
          else:
              raise NotImplementedError("Support for renaming users in Jira "
                                        "< 6.0.0 has been removed.")