code: public void addThreadLocalSQLAuditor(Consumer<String> observer)
  	{
  		List<Consumer<String>> observers = onPrepareStatementWatchers.get();
  
  		if (observers == null)
  		{
  			observers = new CopyOnWriteArrayList<>();
  			onPrepareStatementWatchers.set(observers);
  		}
  
  		observers.add(observer);
  	}
docs: Add an observer to <code>onPrepareStatement</code> calls made by the current Thread until {@link
  #clearThreadLocalObservers()} is
  called
  
  @param observer