code: def evaluator(self, candidates, args):
          
          fitness = []
          if self._use_ants:
              for candidate in candidates:
                  total = 0
                  for c in candidate:
                      total += self.weights[c.element[0]][c.element[1]]
                  last = (candidate[-1].element[1], candidate[0].element[0])
                  total += self.weights[last[0]][last[1]]
                  fitness.append(1 / total)
          else:
              for candidate in candidates:
                  total = 0
                  for src, dst in zip(candidate, candidate[1:] + [candidate[0]]):
                      total += self.weights[src][dst]
                  fitness.append(1 / total)
          return fitness
docs: Return the fitness values for the given candidates.