code: def add_user_to_group(uid, gid, exist_ok=True):
      
      acl_url = urljoin(_acl_url(), 'groups/{}/users/{}'.format(gid, uid))
      try:
          r = http.put(acl_url)
          assert r.status_code == 204
      except DCOSHTTPException as e:
          if e.response.status_code == 409 and exist_ok:
              pass
          else:
              raise
docs: Adds a user to a group within DCOS Enterprise.  The group and
          user must exist.
  
          :param uid: user id
          :type uid: str
          :param gid: group id
          :type gid: str
          :param exist_ok: True if it is ok for the relationship to pre-exist.
          :type exist_ok: bool