OGC helper

Hello,
like I said in my mail with the CLA, I make a contributition that can parse the capabilities of Web Map Service, Tile Map Service and Web Map Tile Service.
I can't find a public server that don't have a CORS restriction also it's difficult to make a sandCastle example.
Nevertheless, if you have an accessible WMS, TMS or WMTS, you can use this code:
var tabCapabilities;
Cesium.OGCHelper.parser({service:'XXX',url:'URL'}).then(function(tab){console.log(tab);tabCapabilities=tab});
console.log(tabCapabilities);

where 
- XXX is type of requested service ('WMS', 'TMS', 'WMTS')
- URL is the url of the capabilities document for geoserver for example it's 
  - 'http://localhost:8090/geoserver/gwc/service/tms/1.0.0' for TMS;
  - 'http://localhost:8090/geoserver/gwc/service/wmts' for WMTS;
  - 'http://localhost:8090/geoserver/ows' for WMS

It's my first pull and I fear that it's a poor contribution also I'm waiting your remarks