Maksim Bolgarin

https://github.com/elastic/go-elasticsearch/blob/996ee1fe69ab40ad65795e48d125b6b4395b6ec3/esutil/bulk_indexer.go#L504 ``` if res.IsError() { atomic.AddUint64(&w.bi.stats.numFailed, uint64(len(w.items))) if w.bi.config.OnError != nil { w.bi.config.OnError(ctx, fmt.Errorf("flush: %s", err)) } return fmt.Errorf("flush: %s", res.String()) } ``` When you enter this if, you will...