Optional<Integer> lastEpoch() {
        return lastEpoch;
    }
{@link CompletedFetch} represents a {@link RecordBatch batch} of {@link Record records} that was returned from the
broker via a {@link FetchRequest}. It contains logic to maintain state between calls to
{@link #fetchRecords(FetchConfig, Deserializers, int)}.
clients/src/main/java/org/apache/kafka/clients/consumer/internals/CompletedFetch.java