private static void append(@NotNull StringBuilder out, @NotNull List<LogEventRecordRequest> requests) {
      boolean isFirst = true;
      for (LogEventRecordRequest request : requests) {
        if (isFirst) {
          isFirst = false;
        } else {
          out.append(",");
        }
        out.append(LogEventSerializer.INSTANCE.toString(request));
      }
    }
private static void append(@NotNull StringBuilder out, @NotNull List<LogEventRecordRequest> requests)