docs: @Nonnull
    public IHasJSCode getJSUpdateCode (@Nonnull final IJSExpression aJSDataVar)
    {
      final JSPackage ret = new JSPackage ();
      // Cleanup old chart
      ret.invoke (JSExpr.ref (getJSChartVar ()), "destroy");
      // Use new chart
      ret.assign (JSExpr.ref (getJSChartVar ()), new JSDefinedClass ("Chart")._new ()
                                                                             .arg (JSExpr.ref (getCanvasID ())
                                                                                         .invoke ("getContext")
                                                                                         .arg ("2d"))
                                                                             .invoke (m_aChart.getJSMethodName ())
                                                                             .arg (aJSDataVar)
                                                                             .arg (getJSOptions ()));
      return ret;
    }