public void add(long offset, AcknowledgeType type) {
        this.acknowledgements.put(offset, type);
    }
Adds an acknowledgement for a specific offset. Will overwrite an existing
acknowledgement for the same offset.

@param offset The record offset.
@param type   The AcknowledgeType.
clients/src/main/java/org/apache/kafka/clients/consumer/internals/Acknowledgements.java