code: def fitness_vs(self):
          "Median Fitness in the validation set"
          l = [x.fitness_vs for x in self.models]
          return np.median(lf fitness_vs(self):
          "Median Fitness in the validation set"
          l = [x.fitness_vs for x in self.models]
          return np.median(l)
docs: Median Fitness in the validation set