Bug 135284 [Viewers] API: need to add methods to StructuredViewer to support ViewerComparator
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
Object root = getRoot();
			for (int i = 0; i < elements.length; i++) {
				boolean add = true;
				for (int j = 0; j < filters.size(); j++) {
					add = ((ViewerFilter) filters.get(j)).select(this, root, elements[i]);
					if (!add) {
						break;
					}
				}
				if (add) {
					filtered.add(elements[i]);
				}
			}
			return filtered.toArray();
		}
		return elements;
	}
	/**
	 * Finds the widget which represents the given element.
	 * <p>
	 * The default implementation of this method tries first to find the widget
	 * for the given element assuming that it is the viewer's input; this is
	 * done by calling <code>doFindInputItem</code>. If it is not found
	 * there, it is looked up in the internal element map provided that this
	 * feature has been enabled. If the element map is disabled, the widget is
	 * found via <code>doFindInputItem</code>.
	 * </p>
	 * 
	 * @param element
	 *            the element