code: def covering_is_required(self, match_set):
          
          assert isinstance(match_set, MatchSet)
          assert match_set.algorithm is self
  
          if self.minimum_actions is None:
              return len(match_set) < len(match_set.model.possible_actions)
          else:
              return len(match_set) < self.minimum_actions
docs: Return a Boolean indicating whether covering is required for the
          current match set. The match_set argument is a MatchSet instance
          representing the current match set before covering is applied.
  
          Usage:
              match_set = model.match(situation)
              if model.algorithm.covering_is_required(match_set):
                  new_rule = model.algorithm.cover(match_set)
                  assert new_rule.condition(situation)
                  model.add(new_rule)
                  match_set = model.match(situation)
  
          Arguments:
              match_set: A MatchSet instance.
          Return:
              A bool indicating whether match_set contains too few matching
              classifier rules and therefore needs to be augmented with a
              new one.