descriptor.setValue( "fraction", 0 );
descriptor.setValue( "message", "{validator.digits}" );
Digits p = AnnotationFactory.create( descriptor );
DigitsValidatorForNumber constraint = new DigitsValidatorForNumber();
constraint.initialize( p );
assertTrue( constraint.isValid( null, null ) );
assertFalse( constraint.isValid( Byte.valueOf( "0" ), null ) );
assertFalse( constraint.isValid( Double.valueOf( "500.2" ), null ) );