mxCodec.decode used not work

[jakim9913]

hello.
I am trying to draw a graph on canvas by importing the created xml.

However, the MxCodec.decode function does not work.
The graph is not rendered or drawn.

origin code

     const xmlDoc = MxUtils.parseXml(data);
            const codec = new MxCodec(xmlDoc);
            codec.decode(xmlDoc.documentElement, this.graph.getModel());

but, Code I found on the internet

let elt = xmlDoc.documentElement.firstChild;
            let cells = [];
            while (elt != null) {
                cells.push(codec.decode(elt));
                this.graph.refresh();
                elt = elt.nextSibling;
            }
            this.graph.addCells(cells);

Both don't work.

Please tell me how to render the xml.
thank you