Derived Property Test

... domain classclass ClassWithDerivedProperty {  Integer a  Integer b  Integer aTimesB  static mapping = {    aTimesB formula: 'A*B'  }}... integration test class ClassWithDerivedPropertyTests extends GroovyTestCase {  void testIsDerivedPropertySearchable () {    /* a*b == 1 */    new ClassWithDerivedProperty(a:1, b:1).save()    new ClassWithDerivedProperty(a:1, b:1).save()    new ClassWithDerivedProperty(a:1, b:1).save()    assert ClassWithDerivedProperty.findAllByATimesB(1).size() == 3    /* a*b = 10 */    new ClassWithDerivedProperty(a:2, b:5).save()    new ClassWithDerivedProperty(a:2, b:5).save()    assert ClassWithDerivedProperty.findAllByATimesB(10).size() == 2  }  void testIsDerivedPropertyNotNull() {    def obj = new ClassWithDerivedProperty(a:2, b:5)    obj.save()    obj = ClassWithDerivedProperty.get(obj.id)    assertNotNull obj    assertNotNull obj.aTimesB //fails!  }}