docs: def rename_group(self, group, newname):
          """Rename contact group
  
          :param group: group data or name of group
          :param newname: of group
          :type group: ``str``, ``unicode``, ``dict``
          :type newname: ``str``, ``unicode``
          :rtype: ``bool``
          """
  
          if isinstance(group, basestring):
              group = self.get_contact(group)
  
          method, url = get_URL('group_update')
  
          payload = {
              'apikey': self.config.get('apikey'),
              'logintoken': self.session.cookies.get('logintoken'),
              'contactgroupid': group['contactgroupid'],
              'name': newname
              }
  
          res = getattr(self.session, method)(url, params=payload)
  
          if res.status_code == 200:
              return True
  
          hellraiser(res)