@Override
    public String toString() {
        return "MultiRecordsSend(" +
            "size=" + size +
            ", totalWritten=" + totalWritten +
            ')';
    }
Get any statistics that were recorded as part of executing this {@link MultiRecordsSend}.
@return Records processing statistics (could be null if no statistics were collected)
clients/src/main/java/org/apache/kafka/common/record/MultiRecordsSend.java