@Override
        public void onFailure(String connector, Throwable cause) {
            state = AbstractStatus.State.FAILED;
            synchronized (this) {
                if (!cancelled) {
                    delegate.onFailure(connector, cause);
                }
            }
        }
Use {@link AbstractStatus.State} since it has all of the states we want,
unlike {@link WorkerConnector.State}.
connect/runtime/src/main/java/org/apache/kafka/connect/runtime/WorkerConnector.java