Worldwind imagery provider access problem

CesiumJS
1

Hello everyone，

I have some problem about the imagery provider. My world wind imagery provider image request URL looks like this:
    http://serverURL?bbox=sw_long,sw_lat,ne_long,ne_lat&width=2048&height=2048&format=image/png

How can I write an API for my imagery provider?

I do some work by changing TileMapServiceImageryProvider.js
   1, I noted the xml part.
   2, I change the buildImageUrl function:

    function buildImageUrl(imageryProvider, x, y, level) {
    var baseLayerSize = 36;
        var tileSizeDegrees = baseLayerSize / Math.pow(2, level),
      w = tileSizeDegrees*x-180,
      s = tileSizeDegrees*(x+1)-180,
      e = tileSizeDegrees*y-90,
      n = tileSizeDegrees*(y+1)-90,
      width = 512,
      height = 512;
      
        var url = imageryProvider._url + "?bbox=" + w +","+ s +","+ e +","+ n +"&width="+ width +"&height="+ height +"&format=image/png";

        var proxy = imageryProvider._proxy;
        if (defined(proxy)) {
            url = proxy.getURL(url);
        }

        return url;
    }
But it lead to a error that the Cesium cannot work without any error report.

I am looking forward your help.
Thank you all!

Aaron