docs: def process(self, candidates):
          """
          :arg list candidates: list of Candidates
          :returns: list of Candidates where score is at least min_score,
                    if and only if one or more Candidates have at least min_score.
                    Otherwise, returns original list of Candidates.
          """
          high_score_candidates = [c for c in candidates if c.score >= self.min_score]
          if high_score_candidates != []:
              return high_score_candidates
          return candidates