docs: private void enterExclusiveThread() {
  		// we use simple get, check, set here, rather than CAS
  		// we don't need lock-style correctness, this is only a sanity-check and we thus
  		// favor speed at the cost of some false negatives in this check
  		Thread previous = currentThread;
  		Thread thisThread = Thread.currentThread();
  
  		if (previous == null) {
  			currentThread = thisThread;
  		}
  		else if (previous != thisThread) {
  			throw new IllegalStateException(
  				"Concurrent access to KryoSerializer. Thread 1: " + thisThread.getName() +
  					" , Thread 2: " + previous.getName());
  		}
  	}