docs: def eval_fitness(self, chromosome):
          """
          Evaluate the polynomial equation using coefficients represented by a
          solution/chromosome, returning its error as the solution's fitness.
  
          return:  fitness value
          """
          coefficients = self.translator.translate_chromosome(chromosome)
          solution_y = self.compute_y(coefficients, self.num_x)
          fitness = -1 * self.compute_err(solution_y, coefficients)
  
          return fitness