message: Add onBeforeSendRequest static event into obsolete ChoicesRestfull for compatibility,
diff: @@ -566,6 +566,17 @@ export class ChoicesRestfull extends ChoicesRestful {
  public static clearCache() {
  ChoicesRestful.clearCache();
  }
  + public static get onBeforeSendRequest(): (
  + sender: ChoicesRestful,
  + options: { request: XMLHttpRequest }
  + ) => void {
  + return ChoicesRestful.onBeforeSendRequest;
  + }
  + public static set onBeforeSendRequest(
  + val: (sender: ChoicesRestful, options: { request: XMLHttpRequest }) => void
  + ) {
  + ChoicesRestful.onBeforeSendRequest = val;
  + }
  }
  Serializer.addClass(
  