Bug 255172 [Import/Export] Warning message in the import wizard is not so helpful
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/wizards/datatransfer/WizardProjectsImportPage.java
Composite listComposite = new Composite(workArea, SWT.NONE);
		GridLayout layout = new GridLayout();
		layout.numColumns = 2;
		layout.marginWidth = 0;
		layout.makeColumnsEqualWidth = false;
		listComposite.setLayout(layout);
		listComposite.setLayoutData(new GridData(GridData.GRAB_HORIZONTAL
				| GridData.GRAB_VERTICAL | GridData.FILL_BOTH));
		projectsList = new CheckboxTreeViewer(listComposite, SWT.BORDER);
		GridData listData = new GridData(GridData.GRAB_HORIZONTAL
				| GridData.GRAB_VERTICAL | GridData.FILL_BOTH);
		projectsList.getControl().setLayoutData(listData);
		projectsList.setContentProvider(new ITreeContentProvider() {
			/*
			 * (non-Javadoc)
			 * 
			 * @see
			 * org.eclipse.jface.viewers.ITreeContentProvider#getChildren(java
			 * .lang.Object)
			 */
			public Object[] getChildren(Object parentElement) {
				return null;
			}
			/*
			 * (non-Javadoc)
			 * 
			 * @see
			 * org.eclipse.jface.viewers.IStructuredContentProvider#getElements
			 * (java.lang.Object)
			 */