code: def get_matches(lf, candidate_set, match_values=[1, -1]):
      
      logger = logging.getLogger(__name__)
      matches = []
      for c in candidate_set:
          label = lf(c)
          if label in match_values:
              matches.append(c)
      logger.info(f"{len(matches)} matches")
      return matches
docs: Return a list of candidates that are matched by a particular LF.
  
      A simple helper function to see how many matches (non-zero by default) an
      LF gets.
  
      :param lf: The labeling function to apply to the candidate_set
      :param candidate_set: The set of candidates to evaluate
      :param match_values: An option list of the values to consider as matched.
          [1, -1] by default.
      :rtype: a list of candidates