final AJsonSerHelper json = new AJsonSerHelper(resp.getOutputStream());
final String pageId = restParams.remove(0);
final String service = restParams.remove(0);
final APresentationPageDefinition pageDef = pageDefs.get(pageId);
if(pageDef == null) {
throw new IllegalArgumentException("no page def with ID '" + pageId + "'");
}
return pageDef.handleRestCall(service, restParams, json);
}