@Override
    public String toString() {
        return "InMemoryTimeOrderedKeyValueChangeBuffer{" +
            "storeName='" + storeName + '\'' +
            ", changelogTopic='" + changelogTopic + '\'' +
            ", open=" + open +
            ", loggingEnabled=" + loggingEnabled +
            ", minTimestamp=" + minTimestamp +
            ", memBufferSize=" + memBufferSize +
            ", \n\tdirtyKeys=" + dirtyKeys +
            ", \n\tindex=" + index +
            ", \n\tsortedMap=" + sortedMap +
            '}';
    }
As of 2.1, there's no way for users to directly interact with the buffer,
so this method is implemented solely to be called by Streams (which
it will do based on the {@code cache.max.bytes.buffering} config.
<p>
It's currently a no-op.
streams/src/main/java/org/apache/kafka/streams/state/internals/InMemoryTimeOrderedKeyValueChangeBuffer.java