When i map columns from the inspected table, i do this:

```
<property name="InstanceName" type="MyNameUserType, MyApp.MyNamespace">
   <column name="Name"/>
   <column name="Name2"/>
</property>

```

How can I make property mapping initialize a UserType with data retrieved by the formula's sql query?

```
<property name="InstanceName" type="MyNameUserType, MyApp.MyNamespace" formula="(...)"/>

```

fails with an exception "wrong number of columns".

Thanks in advance!