import junit.framework.TestCase;
public class EqualsExprTest extends TestCase {
public void testHappy() {
assertEquals(true, new EqualsExpr(new NullExpr(), new NullExpr()).eval(null));
assertEquals(false, new EqualsExpr(new NullExpr(), new StringExpr("foo")).eval(null));
assertEquals(false, new EqualsExpr(new StringExpr("foo"), new NullExpr()).eval(null));
}