code: @Override
  	protected BundleRenderer createRenderer(ResourceBundlesHandler rsHandler, Boolean useRandomParam) {
  
  		Boolean asyncFlag = null;
  		if (StringUtils.isNotEmpty(async)) {
  			asyncFlag = Boolean.valueOf(async);
  		}
  		Boolean deferFlag = null;
  		if (StringUtils.isNotEmpty(defer)) {
  			deferFlag = Boolean.valueOf(defer);
  		}
  		return RendererFactory.getJsBundleRenderer(rsHandler, type, useRandomParam, asyncFlag, deferFlag, crossorigin);
  	}
docs: /*
  (non-Javadoc)
  
  @see
  net.jawr.web.taglib.AbstractResourceBundleTag#createRenderer(net.jawr.web
  .resource.bundle.handler.ResourceBundlesHandler, boolean)