@Test
public void testColumns() {
// columns are initally empty
assertEquals(0, vd.getColumns().size());
// adding a column
ColDef c = new ColDef.QueryColDef(null, "foo");
assertSame(c, vd.addColumn(c));
assertSame(c, vd.getColumn("foo"));
assertEquals(1, vd.getColumns().size());
}
