docs: def set_type(self, form_type, css_class=None):
          """
          Maybe you have a site where you're not allowed to change the python code,
          and for some reason you need to change the form_type in a template, not
          because you want to (because it seems like a bit of a hack) but maybe you
          don't really have a choice.  Then this function was made for you.
  
          Sorry
  
          :param form_type: The new form_type
          :param css_class: If None (default) derrive this from the form_type.
                            If a value is passed in this will be the new css_class
                            for the form
          """
          self.form_type = form_type
          
          if css_class is None:
              self.css_class = self.get_default_css_class(form_type)
          else:
              self.css_class = css_class
          
          return ''