table.addContainerProperty("Col1", String.class, null);
table.addContainerProperty("Col2", String.class, null);
table.addContainerProperty("Col3", String.class, null);
table.setColumnCollapsingAllowed(true);
table.addActionHandler(new Handler() {
final Action H = new Action("Toggle Col2");
final Action[] actions = new Action[] { H };
@Override