code: def get_changes_since(self, change_number, app_changes=True, package_changes=False):
          
          return self.send_job_and_wait(MsgProto(EMsg.ClientPICSChangesSinceRequest),
                                        {
                                         'since_change_number': change_number,
                                         'send_app_info_changes': app_changes,
                                         'send_package_info_changes': package_changes,
                                        },
                                        timeout=15
                                       )
docs: Get changes since a change number
  
          :param change_number: change number to use as stating point
          :type change_number: :class:`int`
          :param app_changes: whether to inclued app changes
          :type app_changes: :class:`bool`
          :param package_changes: whether to inclued package changes
          :type package_changes: :class:`bool`
          :return: `CMsgClientPICSChangesSinceResponse <https://github.com/ValvePython/steam/blob/39627fe883feeed2206016bacd92cf0e4580ead6/protobufs/steammessages_clientserver.proto#L1171-L1191>`_
          :rtype: proto message instance, or :class:`None` on timeout