@Override
    public String toString() {
        return "WorkerState{" +
                "url='" + url() + '\'' +
                ", offset=" + offset() +
                ", " + assignment +
                '}';
    }
This method returns which was the assignment of connectors and tasks on a worker at the
moment that its state was captured by this class.

@return the assignment of connectors and tasks
connect/runtime/src/main/java/org/apache/kafka/connect/runtime/distributed/ExtendedWorkerState.java