Utility Class to find SFDC current Org API Version

UtilityClassForSFDC.cls

//Utility to find SFDC current Org API Version
public class UtilityClassForSFDC{
    
    public static decimal findAPIVersionOfOrg(){
        HttpRequest req = new HttpRequest();
        req.setHeader('Authorization', 'Bearer ' + UserInfo.getSessionID());
        req.setHeader('Content-Type', 'application/json');
        String domainUrl=URL.getSalesforceBaseUrl().toExternalForm();
        system.debug('********domainUrl:'+domainUrl);
        req.setEndpoint(domainUrl+'/services/data');
        req.setMethod('GET');

        Http h = new Http();
        HttpResponse res = h.send(req);
        system.debug(res.getBody()); 

        String response=res.getBody();
        String apiVersion='';
        List<decimal> versionList=new List<decimal>();
        JSONParser  parser = JSON.createParser(Response);
        while (parser.nextToken() != null) {
         if ((parser.getCurrentToken() == JSONToken.FIELD_NAME)){
          String fieldName = parser.getText();
             if(fieldName == 'version'){
                parser.nextToken(); 
                 versionList.add(decimal.valueof(parser.getText()));
             }
          }
        }
        versionList.sort();
        system.debug('*******versionList'+versionList);
        system.debug('******Current API version:'+versionList[versionList.size()-1]);
        return versionList[versionList.size()-1];
    }
}