public void addGap(long offset) {
        acknowledgements.put(offset, null);
    }
Adds a gap for the specified offset. This means the broker expected a record at this offset
but when the record batch was parsed, the desired offset was missing. This occurs when the
record has been removed by the log compactor.

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