code: public void createPartControl(Composite parent) {
  		viewer = new TreeViewer(parent, SWT.MULTI | SWT.H_SCROLL | SWT.V_SCROLL | SWT.BORDER);
  		viewer.setContentProvider(new ViewContentProvider());
  		viewer.setLabelProvider(new ViewLabelProvider());
  		viewer.setInput(createDummyModel());
  	}
docs: This is a callback that will allow us to create the viewer and initialize
  it.