docs: def _subtitlesAdded(self, path, subNos):
          """When subtitle is added, all syncPoints greater or equal than a new
          subtitle are incremented."""
          def action(current, count, model, row):
              _setSubNo(current + count, model, row)
  
          def count(current, nos):
              ret = 0
              for no in nos:
                  if current >= no:
                      ret += 1
                      # consider: current = 0, nos = [0, 1, 2, 3]
                      # in that case, current should be prepended by all nos
                      current += 1
              return ret
  
          self._changeSubNos(path, subNos, count, action)