code: def as_widget(self, widget=None, attrs=None, only_initial=False):
          
          if not widget:
              widget = self.field.widget
  
          attrs = attrs or {}
          auto_id = self.auto_id
          if auto_id and 'id' not in attrs and 'id' not in widget.attrs:
              if not only_initial:
                  attrs['id'] = auto_id
              else:
                  attrs['id'] = self.html_initial_id
  
          name = ""
          return widget.render(name, self.value(), attrs=attrs)
docs: Renders the field by rendering the passed widget, adding any HTML
          attributes passed as attrs.  If no widget is specified, then the
          field's default widget will be used.