code: public static String[] getOAuthKeysForApp(App app, String prefix) {
  		prefix = StringUtils.removeEnd(prefix + "", Config.SEPARATOR);
  		String appIdKey = prefix + "_app_id";
  		String secretKey = prefix + "_secret";
  		String[] keys = new String[]{"", ""};
  
  		if (app != null) {
  			Map<String, Object> settings = app.getSettings();
  			if (settings.containsKey(appIdKey) && settings.containsKey(secretKey)) {
  				keys[0] = settings.get(appIdKey) + "";
  				keys[1] = settings.get(secretKey) + "";
  			} else if (app.isRootApp()) {
  				keys[0] = Config.getConfigParam(appIdKey, "");
  				keys[1] = Config.getConfigParam(secretKey, "");
  			}
  		}
  		return keys;
  	}
docs: Return the OAuth app ID and secret key for a given app by reading the app settings, or the config file.
  @param app the app in which to look for these keys
  @param prefix a service prefix: "fb" for facebook, "tw" for twitter etc. See {@link Config}
  @return an array ["app_id", "secret_key"] or ["", ""]