@Override
        public void onConnectorConfigUpdate(String connector) {
            // TODO: move connector configuration update handling here to be consistent with
            //       the semantics of the config backing store

            synchronized (StandaloneHerder.this) {
                configState = configBackingStore.snapshot();
            }
        }
This method performs a few checks for external requests to modify (alter or reset) connector offsets and
completes the callback exceptionally if any check fails.
@param connName the name of the connector whose offsets are to be modified
@param cb callback to invoke upon completion
@return true if all the checks passed, false otherwise
connect/runtime/src/main/java/org/apache/kafka/connect/runtime/standalone/StandaloneHerder.java