code: def convert_widgets(self):
          
          for field in self.base_fields.values():
              try:
                  new_widget = field.get_converted_widget()
              except AttributeError:
                  pass
              else:
                  if new_widget:
                      field.widget = new_widget
docs: During form initialization, some widgets have to be replaced by a counterpart suitable to
          be rendered the AngularJS way.