docs: def add_text_widget(self, text=None, custom_title=None, collapsible=True, collapsed=False):
          """
          Add a KE-chain Text widget to the customization.
  
          The widget will be saved to KE-chain.
  
          :param text: The text that will be shown by the widget.
          :type text: basestring or None
          :param custom_title: A custom title for the text panel::
              * None (default): No title
              * String value: Custom title
          :type custom_title: basestring or None
          :param collapsible: A boolean to decide whether the panel is collapsible or not (default True)
          :type collapsible: bool
          :param collapsed: A boolean to decide whether the panel is collapsed or not (default False)
          :type collapsible: bool
          :raises IllegalArgumentError: When unknown or illegal arguments are passed.
          """
          # Declare text widget config
          config = {
              "xtype": ComponentXType.HTMLPANEL,
              "filter": {
                  "activity_id": str(self.activity.id),
              }
          }
  
          # Add text and custom title
          if text:
              config['html'] = text
          if custom_title:
              show_title_value = "Custom title"
              title = custom_title
          else:
              show_title_value = "No title"
              title = None
          config['collapsible'] = collapsible
          # A widget can only be collapsed if it is collapsible in the first place
          if collapsible:
              config['collapsed'] = collapsed
          else:
              config['collapsed'] = False
          config['title'] = title
          # Declare the meta info for the property grid
          meta = {
              "activityId": str(self.activity.id),
              "customTitle": title,
              "collapsible": collapsible,
              "collapsed": collapsed,
              "html": text,
              "showTitleValue": show_title_value
          }
  
          self._add_widget(dict(config=config, meta=meta, name=WidgetNames.HTMLWIDGET))