Bug 127861 [DataBinding] Mark API provisional
bundles/org.eclipse.jface.databinding/src/org/eclipse/jface/databinding/updatables/UnionSet.java
break;
			}
		}
	};
	private int staleCount = 0;
	
    protected void processStale(final boolean isStale) {
    	if (isStale) {
    		staleCount++;
    		
    		if (staleCount == 1) {
    			fireStale(true);
    		}
    	} else {
    		staleCount--;
    		
    		if (staleCount == 0) {
    			fireStale(false);
    		}
    	}
	}
    
    public boolean isStale() {
    	
    	if (refCounts != null) {
    		return (staleCount > 0);
    	}
    
    	IReadableSet[] children = (IReadableSet[]) childSets.toArray(new IReadableSet[childSets.size()]);
    	for (int i = 0; i < children.length; i++) {