Bug 127861 [DataBinding] Mark API provisional
bundles/org.eclipse.jface.databinding/src/org/eclipse/jface/databinding/updatables/InverseMapping.java
* Removes the given element from the cache. Fills in an ElementReport to
     * indicate  
     * 
     * @param element element to remove
     * @param status ElementReport. Will contain the old value of the element and
     * the number of other domain objects that share this value.
     * @return
     */
    public Collection removeMapping(Object element) {
        Object adapter = elementsToAdapters.remove(element);
        if (adapter != null) {
            Collection elements = (Collection) adaptersToElementCollection.get(adapter);
            if (elements != null) {
                elements.remove(element);
                if (elements.isEmpty()) {
                    adaptersToElementCollection.remove(adapter);
                }
                
                return elements;
            }
        }
        
        return Collections.EMPTY_SET;
    }
    public void dispose() {
        adaptersToElementCollection.clear();
        elementsToAdapters.clear();
    }
}