docs: def search(self, string, default=None):
          """Use re.search to find the result
  
          :rtype: list"""
          default = default if default else []
          result = [item[1] for item in self.container if item[0].search(string)]
          if self.ensure_mapping:
              assert len(result) < 2, "%s matches more than one pattern: %s" % (
                  string,
                  result,
              )
          return result if result else default