@Override
                public void onFailure(RuntimeException e) {
                    offsetFetcherUtils.onFailedResponseForValidatingPositions(fetchPositions, e);
                }
For each partition which needs validation, make an asynchronous request to get the end-offsets for the partition
with the epoch less than or equal to the epoch the partition last saw.

<p/>

Requests are grouped by Node for efficiency.
clients/src/main/java/org/apache/kafka/clients/consumer/internals/OffsetFetcher.java