code: def render_next_step(self, form, **kwargs):
          
          # get the form instance based on the data from the storage backend
          # (if available).
          next_step = self.steps.next
          new_form = self.get_form(next_step,
              data=self.storage.get_step_data(next_step),
              files=self.storage.get_step_files(next_step))
  
          # change the stored current step
          self.storage.current_step = next_step
          return self.render(new_form, **kwargs)
docs: THis method gets called when the next step/form should be rendered.
          `form` contains the last/current form.