Bug 317803 [CommonNavigator] NPE in WorkingSetsContentProvider
bundles/org.eclipse.ui.navigator.resources/src/org/eclipse/ui/internal/navigator/workingsets/WorkingSetsContentProvider.java
case ProjectExplorer.PROJECTS :
						return getWorkingSetElements(workingSet);
				}
			}
			return getWorkingSetElements(workingSet);
		}
		return NO_CHILDREN;
	}
	private IAdaptable[] getWorkingSetElements(IWorkingSet workingSet) {
		IAdaptable[] children = workingSet.getElements();
		for (int i = 0; i < children.length; i++) {
			Object resource = children[i].getAdapter(IResource.class);
			if (resource instanceof IProject)
				children[i] = (IProject) resource;
		}
		return children;
	}
	public Object getParent(Object element) {
		if (helper != null)
			return helper.getParent(element);
		return null;
	}
	public boolean hasChildren(Object element) {
		return true;
	}
	public Object[] getElements(Object inputElement) {
		return getChildren(inputElement);
	}
	public void dispose() {
		helper = null;