@Override
        public String toString() {
            return this.getClass().getSimpleName();
        }
Construct and enqueue a {@link MetadataChangeEvent} with a given completion handler. In production use cases,
this handler is a no-op. This method exists so that we can add additional logic in our unit tests to wait for the
enqueued event to finish executing.
metadata/src/main/java/org/apache/kafka/metadata/migration/KRaftMigrationDriver.java