i added a unique index to my db

CREATE UNIQUE INDEX d_7col_uni_idx ON m.dv
(fk_id, name, coalesce(make,'~~~NULL~~~'), coalesce(model,'~~~NULL~~~')
, coalesce(type,'~~~NULL~~~'), coalesce(cbo_id,-1), coalesce(pt,'~~~NULL~~~'))
WHERE expiration_date IS NULL;

i'm using hbm2java to generate my java classes from the db by providing a reveng.xml file to help. adding this constraint causes the java code to have :

@Table(name="dv"
, uniqueConstraints = @UniqueConstraint(columnNames={"fk_id", "name", "(COALESCE(make, '~~~NULL~~~'::character varying))", "(COALESCE(model, '~~~NULL~~~'::character varying))", "(COALESCE(type, '~~~NULL~~~'::character varying))", "(COALESCE((cbo_id)::integer, (-1)))", "(COALESCE(pt, '~~~NULL~~~'::character varying))"})
)

When running my unit tests, I get an exception:

java.lang.NullPointerException
at org.hibernate.mapping.Constraint$ColumnComparator.compare(Constraint.java:134)

My quick thought is to just get hibernate/hbm2java to ignore that constraint and not have that annotation on the generated class. is this possible?