code: def export(cls, folder, particles, datetimes):
          
          if not os.path.exists(folder):
              os.makedirs(folder)
  
          particle_path = os.path.join(folder, 'particles.pickle')
          f = open(particle_path, "wb")
          pickle.dump(particles, f)
          f.close()
  
          datetimes_path = os.path.join(folder, 'datetimes.pickle')
          f = open(datetimes_path, "wb")
          pickle.dump(datetimes, f)
          f.close()
docs: Export particle and datetime data to Pickled objects.
              This can be used to debug or to generate different output
              in the future.