Bug 127861 [DataBinding] Mark API provisional
bundles/org.eclipse.jface.databinding/src/org/eclipse/jface/databinding/updatables/LazyCalculatedValue.java
ILazyReadableValue {
	
	private boolean dirty = true;
	private Object cachedValue = null;
	
	/** 
	 * Dependencies list. This is a collection that contains no duplicates. It is normally
	 * an ArrayList to conserve memory, but if it ever grows above a certain number of elements, 
	 * a HashSet is substited to conserve runtime.
	 */ 
	private Collection dependencies = new ArrayList();
	
	/**
	 * Stale count. This is equal to the number of currently-stale dependencies. The 
	 * stale count is reset to zero each time before calling computeValue.
	 */
	private int staleCount = 0;