containerLayout.verticalSpacing = 3;
parent.setLayout(containerLayout);
viewer = new TreeViewer(parent, SWT.SINGLE | SWT.H_SCROLL | SWT.V_SCROLL);
viewer.setContentProvider(new TestViewContentProvider(getViewSite()));
viewer.setLabelProvider(new TestViewLabelProvider());
viewer.getTree().setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
viewer.getTree().setLinesVisible(true);
viewer.setInput(TestTreeModel.getInstance());