How to use the mermaid/src/diagrams/gantt/ganttRenderer.setConf function in mermaid

gitGraphRenderer.setConf(config.git);
        gitGraphRenderer.draw(txt, svgId, false);
        break;
      case 'flowchart':
        config.flowchart.arrowMarkerAbsolute = config.arrowMarkerAbsolute;
        flowRenderer.setConf(config.flowchart);
        flowRenderer.draw(txt, svgId, false);
        break;
      case 'sequence':
        config.sequence.arrowMarkerAbsolute = config.arrowMarkerAbsolute;
        sequenceRenderer.setConf(config.sequence);
        sequenceRenderer.draw(txt, svgId);
        break;
      case 'gantt':
        config.gantt.arrowMarkerAbsolute = config.arrowMarkerAbsolute;
        ganttRenderer.setConf(config.gantt);
        ganttRenderer.draw(txt, svgId);
        break;
      case 'class':
        config.class.arrowMarkerAbsolute = config.arrowMarkerAbsolute;
        classRenderer.setConf(config.class);
        classRenderer.draw(txt, svgId);
        break;
      default:
        throw new Error('Invalid graph type.');
    }
    elt.parentNode.replaceChild(containerElt.firstChild, elt);
  } catch (e) {
    console.error(e); // eslint-disable-line no-console
  }
};