code: def catch_lane_change(self):
          
          if self.current.lane_name:
              if self.current.old_lane and self.current.lane_name != self.current.old_lane:
                  # if lane_name not found in pool or it's user different from the current(old) user
                  if (self.current.lane_id not in self.current.pool or
                              self.current.pool[self.current.lane_id] != self.current.user_id):
                      self.current.log.info("LANE CHANGE : %s >> %s" % (self.current.old_lane,
                                                                        self.current.lane_name))
                      if self.current.lane_auto_sendoff:
                          self.current.sendoff_current_user()
                      self.current.flow_enabled = False
                      if self.current.lane_auto_invite:
                          self.current.invite_other_parties(self._get_possible_lane_owners())
                      return True
docs: trigger a lane_user_change signal if we switched to a new lane
          and new lane's user is different from current one