code: def str_search(self, search: str) -> List[HistoryItem]:
          
          def isin(history_item):
              """filter function for string search of history"""
              sloppy = utils.norm_fold(search)
              return sloppy in utils.norm_fold(history_item) or sloppy in utils.norm_fold(history_item.expanded)
          return [item for item in self if isin(item)]
docs: Find history items which contain a given string
  
          :param search: the string to search for
          :return: a list of history items, or an empty list if the string was not found