@Override
    public Future<Void> set(final Map<ByteBuffer, ByteBuffer> values, final Callback<Void> callback) {
        SetCallbackFuture producerCallback = new SetCallbackFuture(values.size(), callback);

        for (Map.Entry<ByteBuffer, ByteBuffer> entry : values.entrySet()) {
            ByteBuffer key = entry.getKey();
            ByteBuffer value = entry.getValue();
            offsetLog.send(key == null ? null : key.array(), value == null ? null : value.array(), producerCallback);
        }

        return producerCallback;
    }
Stop reading from and writing to the offsets topic, and relinquish resources allocated for interacting
with it, including Kafka clients.
<p>
The admin client derived from the given {@link Supplier} will not be closed and it is the
caller's responsibility to manage its lifecycle accordingly.
connect/runtime/src/main/java/org/apache/kafka/connect/storage/KafkaOffsetBackingStore.java