docs: @Override
    public void unregisterXAResource(String uniqueName, XAResource xaResource) {
      Ehcache3XAResourceProducer xaResourceProducer = producers.get(uniqueName);
  
      if (xaResourceProducer != null) {
        boolean found = xaResourceProducer.removeXAResource(xaResource);
        if (!found) {
          throw new IllegalStateException("no XAResource " + xaResource + " found in XAResourceProducer with name " + uniqueName);
        }
        if (xaResourceProducer.isEmpty()) {
          xaResourceProducer.close();
          producers.remove(uniqueName);
        }
      } else {
        throw new IllegalStateException("no XAResourceProducer registered with name " + uniqueName);
      }
    }