title: Get intermediate results from NSGAII genetic algorithm from JmetalPy
body: <p>I Have a code that solves a optimization problem using NSGAII from jmetalpy</p>
  <pre><code>algorithm = NSGAII(
              problem=problem,
              population_size=50, #50
              offspring_population_size=50, #50
              mutation=PolynomialMutation(probability=1.0 / problem.number_of_variables, distribution_index=20),
              crossover=SBXCrossover(probability=1.0, distribution_index=20),
              termination_criterion=StoppingByEvaluations(max=3000) #3000
          )
  
          algorithm.run()
          
          front = get_non_dominated_solutions(algorithm.get_result())
  </code></pre>
  <p>This all works fine. However now I would like to get a feeling for the progress of the optimization by obtaining the results of the intermediate generations. Does not need to be all 3000 of them. Every 5, 10 100 or something will do fine. I have not been able to find this. Can anyone help?</p>