Bug 275929 [CommonNavigator] IPipelinedTreeContentProvider.getPipelinedElements() not ever called
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/NavigatorContentServiceContentProvider.java
return (TreePath[]) paths.toArray(new TreePath[paths.size()]);
		 
	}
  
	/**
	 * Get the element from an element or tree path argument.
	 * @param parentElementOrPath the element or tree path
	 * @return the element
	 */
	private Object internalAsElement(Object parentElementOrPath) {
		if (parentElementOrPath instanceof TreePath) {
			TreePath tp = (TreePath) parentElementOrPath;
			if (tp.getSegmentCount() > 0) {
				return tp.getLastSegment();
			}
			
			return viewer.getInput();
		}
		return parentElementOrPath;
	}
	
	class CyclicPathException extends Exception {
		private static final long serialVersionUID = 2111962579612444989L;
		protected CyclicPathException(TreePathCompiler compiler, Object invalidSegment, boolean asChild) {
			super("Cannot add " + invalidSegment +  
					" to the list of segments in " + compiler +   
					(asChild ? " as a child." : " as a parent.") ); 
		}
	}
	class TreePathCompiler {