code: def old(self):
          
          ori = self.original.action
          if isinstance(ori, (
                  types.ChannelAdminLogEventActionChangeAbout,
                  types.ChannelAdminLogEventActionChangeTitle,
                  types.ChannelAdminLogEventActionChangeUsername
          )):
              return ori.prev_value
          elif isinstance(ori, types.ChannelAdminLogEventActionChangePhoto):
              return ori.prev_photo
          elif isinstance(ori, types.ChannelAdminLogEventActionChangeStickerSet):
              return ori.prev_stickerset
          elif isinstance(ori, types.ChannelAdminLogEventActionEditMessage):
              return ori.prev_message
          elif isinstance(ori, (
                  types.ChannelAdminLogEventActionParticipantToggleAdmin,
                  types.ChannelAdminLogEventActionParticipantToggleBan
          )):
              return ori.prev_participant
          elif isinstance(ori, (
                  types.ChannelAdminLogEventActionToggleInvites,
                  types.ChannelAdminLogEventActionTogglePreHistoryHidden,
                  types.ChannelAdminLogEventActionToggleSignatures
          )):
              return not ori.new_value
          elif isinstance(ori, types.ChannelAdminLogEventActionDeleteMessage):
              return ori.message
          elif isinstance(ori, types.ChannelAdminLogEventActionDefaultBannedRights):
              return ori.prev_banned_rights
docs: The old value from the event.