@Test
public void testDiffConstraintType() {

    column1.setConstraintValueType( BaseSingleFieldConstraint.TYPE_PREDICATE );
    column2.setConstraintValueType( BaseSingleFieldConstraint.TYPE_RET_VALUE );
    checkSingleDiff( FIELD_CONSTRAINT_VALUE_TYPE,
                     BaseSingleFieldConstraint.TYPE_PREDICATE,
                     BaseSingleFieldConstraint.TYPE_RET_VALUE,
                     column1,
                     column2 );
}